• TABLE OF CONTENTS
HIDE
 Title Page
 Table of Contents
 Introduction
 The cows contribution to family...
 What is a profitable cow?
 Breeds of dairy cattle
 The dairy herd: sire and dam
 Selection of a herd sire
 Breeding records
 Keeping dairy records
 Raising herd replacements
 Feeding methods for dairy...
 Factors affecting milk yield
 Factors affecting the butterfat...
 Economic phases of dairying
 Average useful life span and reason...
 Acknowledgement














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 599
Title: Dairy cattle and their care
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027295/00001
 Material Information
Title: Dairy cattle and their care
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 55 p. : ill. ; 23 cm.
Language: English
Creator: Arnold, P. T. Dix, 1902-
Becker, R. B ( Raymond Brown ), 1892-1989
Spurlock, A. H
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: [1958]
 Subjects
Subject: Dairy cattle -- Florida   ( lcsh )
Dairy farming -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references.
Statement of Responsibility: P.T. Dix Arnold, R.B. Becker and A.H. Spurlock.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00027295
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000927023
oclc - 18287596
notis - AEN7726

Table of Contents
    Title Page
        Page 1
    Table of Contents
        Page 2
    Introduction
        Page 3
    The cows contribution to family living in Florida
        Page 3
        Page 4
    What is a profitable cow?
        Page 5
        Page 6
    Breeds of dairy cattle
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    The dairy herd: sire and dam
        Page 12
        Page 13
        Page 14
    Selection of a herd sire
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
    Breeding records
        Page 26
        Page 27
        Page 28
    Keeping dairy records
        Page 29
    Raising herd replacements
        Page 30
    Feeding methods for dairy calves
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
    Factors affecting milk yield
        Page 39
        Page 40
        Page 41
        Page 42
    Factors affecting the butterfat content of milk
        Page 43
        Page 44
        Page 45
    Economic phases of dairying
        Page 46
        Page 47
        Page 48
        Page 49
    Average useful life span and reason for disposal of dairy cattle
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
    Acknowledgement
        Page 55
Full Text

UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
J. R. BECKENBACH, Director
-GAINESVILLE, FLORIDA
BULLETIN 599








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CONTENTS
Page
INTRODUCTION ..................................... -- .... .....- ------ ---- ---- ---- 3
THE COW'S CONTRIBUTION TO FAMILY LIVING IN FLORIDA-.........---------------. 3
WHAT IS A PROFITABLE COW? ...............................---- 5
BREEDS OF DAIRY CATTLE ................................ -... 7
THE DAIRY HERD: SIRE AND DAM --..................... ... ------ 12
What Gives Value to a Cow ?....................-.....-..-----. 12
Relation of Dam to Production of Daughters..............---.--------- 13
Building on Cow Families ................... ........--- 14
SELECTION OF A HERD SIRE ....................... -- --- 15
Care and Management of the Bull.................................. 18
Sampling and Proving the Sire ............. ..------------ 21
Length of Useful Service ............. .......... ---.---- -------- 23
Natural Causes of Termination of Usefulness --......... .--------- 23
BREEDING RECORDS .........-----.... ...... ..-----------..--. -.... 26
KEEPING DAIRY RECORDS ................--.. .....-- 29
Cooperative Record Systems........................... --.. 29
RAISING HERD REPLACEMENTS- -.................- ---- -- 30
Dairy Calves ----................ --------....-- 30
The Calf at Birth .......... ....... 30
FEEDING METHODS FOR DAIRY CALVES- ......-...---------- ---- 31
Taking the Calf from the Cow......... -.....------- ----- 31
Colostrum as Calf Feed......... -.-- --- ------------ 32
Raising Calves on Nurse Cows.............-------------- 32
The Nipple Bucket...-...........------------------- 32
Feeding Whole Milk and Skimmilk -..........--.---- -------- 33
Limited Milk Feeding-Dry Method .............--- --- 33
Liquid Milk Substitutes and Gruels.. ............----- --- 33
Leafy Forages .......... ---- ----.------------- 34
Precautions in Calf Management ..... -............ 34
Housing for Calves... ....................... ......... 35
Feed from Weaning to Breeding Age .............................. 36
Age and Size to Breed Heifers.............. ---------- -- 36
Feed from Breeding to Calving Time....... ........---- 37
Mineral Supplements for Cattle -.... .................. -- ... 37
FACTORS AFFECTING MILK YIELD -....................-------- ... -- 39
Season of Calving Affects Yearly Milk Yield.............. ------------- 39
Age Influences Milk Production. -- -.---------- 40
Length of Dry Period Affects Milk Yield....-............-.....---- 40
Mineral Supplements as Related to Milk Yield.......... 41
Managed Milking.............--............. ---- --- 42
FACTORS AFFECTING THE BUTTERFAT CONTENT OF MILK.............--- ----- 43
Variations in the Butterfat Content of Milk ................. --------- 43
Richness of Morning and Evening Milk ................ .- ------- 44
Age Influences Average Butterfat Test.. ---... .------ ..--- 45
Effect of Insufficient Forages ---- -- --.- ............ 45
ECONOMIC PHASES OF DAIRYING...........----------------- -- 46
What Makes a Successful Dairy Farm Operation? -.......----------- 46
Season of Calving in Relation to Milk Sales.....................-- ----- 47
W hen Should a Cow Be Culled?-..........................-------- -- -- 48
Raising versus Purchasing Replacements.... ..-------------- 49
AVERAGE USEFUL LIFESPAN AND REASONS FOR DISPOSAL OF DAIRY CATTLE-. 50
Depreciation of Dairy Cows ......................... -..---- 53
ACKNOWLEDGMENTS ....... ---------------------------... 55
August 1958








Dairy Cattle and Their Care

INTRODUCTION
Dairy cattle and methods of management have been improved
in recent years, resulting in much progress in the dairy industry.
This progress in Florida is the result of more local sources of good
breeding stock, artificial breeding with desirably proved sires,
and an increased proportion of home-raised replacements. Sup-
plies of home-grown and locally-produced feeds, supplemental
silage crops, and use of proper mineral supplements have con-
tributed to economical dairying in Florida. Also there have
been increased plantings of pastures with adapted grasses and
legumes. These are being fertilized more heavily and their man-
agement intensified to provide good forage for a longer time in
the year. These improvements have increased milk production
per cow, per acre and per man-hour of labor.
There are three distinct classes of dairying in Florida: the
strictly commercial dairy, dairying as a part of general farming,
and the family cows. Many problems apply to all classes of
dairy farming, but each class also has some special management
problems.
Every farm has a marked need for a supply of milk for home
use, especially where there are children. When milk is available,
less money is required to buy groceries for the family living;
folks live better and are more healthy. A higher standard of
living is maintained for the entire family, since money saved on
groceries is available for other needs of farm life. Even a medi-
ocre cow may render valuable service as a family cow.

THE COW'S CONTRIBUTION TO FAMILY LIVING
IN FLORIDA
The contribution of dairying to the living of farm families in
Florida has been studied in several areas. On 220 specialized
dairy farms, families of farm operators consumed milk and milk
products equivalent to an average of 3,948 pounds (459 gallons)
of whole milk in a year. The average laborer on these farms
used an additional 896 pounds (104 gallons) per dairy farm. One
dairy and 28 farms in a general farming area on which dairy
cows were kept for sale of dairy products were surveyed. Fam-
ilies of farm operators on these general farms used an average
of 3,628 pounds of milk for home consumption during the year,
and allowed an additional 318 pounds to laborers.








Dairy Cattle and Their Care

INTRODUCTION
Dairy cattle and methods of management have been improved
in recent years, resulting in much progress in the dairy industry.
This progress in Florida is the result of more local sources of good
breeding stock, artificial breeding with desirably proved sires,
and an increased proportion of home-raised replacements. Sup-
plies of home-grown and locally-produced feeds, supplemental
silage crops, and use of proper mineral supplements have con-
tributed to economical dairying in Florida. Also there have
been increased plantings of pastures with adapted grasses and
legumes. These are being fertilized more heavily and their man-
agement intensified to provide good forage for a longer time in
the year. These improvements have increased milk production
per cow, per acre and per man-hour of labor.
There are three distinct classes of dairying in Florida: the
strictly commercial dairy, dairying as a part of general farming,
and the family cows. Many problems apply to all classes of
dairy farming, but each class also has some special management
problems.
Every farm has a marked need for a supply of milk for home
use, especially where there are children. When milk is available,
less money is required to buy groceries for the family living;
folks live better and are more healthy. A higher standard of
living is maintained for the entire family, since money saved on
groceries is available for other needs of farm life. Even a medi-
ocre cow may render valuable service as a family cow.

THE COW'S CONTRIBUTION TO FAMILY LIVING
IN FLORIDA
The contribution of dairying to the living of farm families in
Florida has been studied in several areas. On 220 specialized
dairy farms, families of farm operators consumed milk and milk
products equivalent to an average of 3,948 pounds (459 gallons)
of whole milk in a year. The average laborer on these farms
used an additional 896 pounds (104 gallons) per dairy farm. One
dairy and 28 farms in a general farming area on which dairy
cows were kept for sale of dairy products were surveyed. Fam-
ilies of farm operators on these general farms used an average
of 3,628 pounds of milk for home consumption during the year,
and allowed an additional 318 pounds to laborers.






Florida Agricultural Experiment Stations


From 22 to 61 percent of the farms in 11 areas where fruit,
truck and other crops were the main sources of income had one
or more family cows. These provided from 101 to 445 gallons of
whole milk per farm, the average being 3,543 pounds (412 gal-
lons) per family per year. About one-fifth of these farms had
only one cow, so that milk was unavailable when she was dry.
Milk cows were owned on 85 of 105 farms surveyed in Marion
County. Twelve were dairy farms, while the majority kept one
or more cows mainly for family use. Only 37 farms had an ade-

Fig. 1.-A fertilized pasture of White clover and grass can provide a
considerable proportion of the nutrients needed by dairy cows. This scene
is at Holly Hill Dairy near Jacksonville.


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Dairy Cattle and Their Care


quate supply of milk throughout the year. An adequate supply
was considered a quart of whole milk per child and a pint per
adult each day. The importance of milk in the food supply is
seen in the fact that consumption of milk and dairy products on
these 37 farms during a year was equivalent to over 400 gallons
of whole milk per family. A good type of family cow is shown
in Figure 2.


Fig. 2.-Family cows contribute much to the welfare of rural people.
A liberal supply of whole milk and dairy products makes an appreciable
contribution to good living and health.

WHAT IS A PROFITABLE COW?
How much milk should a cow produce to pay her way? The
answer may be based upon sources of feed and labor and use of
the milk. A family cow often derives a large part of her nutrient
requirements from locally-grown feeds. She is cared for largely
by family labor which would not receive wages otherwise at the
same hours. Little capital is invested for shelter or in equip-
ment. Medium or even low-producing cows may save on the
family budget and render a real service by providing health-
giving food at a minimum cash outlay.
Cows on general farms obtain part of their feed by gleaning
fields from which cash crops have been marketed. They convert
the coarse parts of many crops into milk for the farm family and
for sale. A large proportion of the labor is performed by the







Florida Agricultural Experiment Stations


farmer and his family. The hours spent with the livestock allow
more efficient use of labor. However, more equipment is neces-
sary to care for the dairy products. Cows must be at least me-
dium producers to return a profit on general farms.
Only medium to high-producing cows will meet operating ex-
penses on a commercial dairy farm and leave any margin for
returns to the operator. Whether or not a particular cow will
pay her way in a commercial dairy depends upon the feeding prac-
tices, cost of feed, labor and other expenses, amount of labor
and efficiency in its use, and the distribution of management and
overhead operating costs. Many of these cost items have varied
as much as 100 percent between neighboring dairies.
High quality milk is produced by healthy, well-fed cows in
a sanitary manner and kept cold until it is consumed. The com-
mercial dairy requires more capital for equipment and for build-
ings. To produce high quality market milk, dairy farms have
a larger investment in equipment for refrigeration, sterilization
and washing of milk utensils than is needed on general farms.
These are an essential part of the costs of producing high quality
market milk.
Management of dairy cows is affected materially by the
character of the market for dairy products. A commercial dairy
may furnish a steady supply of milk to an industrial community
with a stable population. On the other hand, the dairy may need
peak production during a period of tourist trade. The season of
freshening for cows on general farms may be timed to bring the
larger part of the dairy products at the time of highest market
prices, or to produce milk mainly from such crops as pastures or
fields that are ready to be gleaned after the harvest of cash
crops. With two family cows, one may be dry while the other
is in milk, for an adequate supply over the year. Some practices
of dairy herd management apply to cows in dairies, those on
general farms and family cows, while other practices meet spe-
cific situations.
Management of the dairy cows on the general farm involves
a number of factors. These factors include convenient distribu-
tion of labor between crop production and care of the cows,
amount of pasture and cultivated fields to be grazed, the season
at which these are available, seasonal demand for whole milk or
cream, and the relative market price of these products from sea-
son to season.







Dairy Cattle and Their Care


The owners of family cows are interested in a steady supply
of milk from pasture grasses and from unmarketable parts of
crops. Only a limited amount of feed is purchased for the cow,
as in most instances an extra supply of milk is not desired be-
yond the amount used by the family as whole milk, cream, but-
ter, cottage cheese, ice cream and for cooking purposes. Sur-
plus milk may be fed to calves, chickens or pigs.

BREEDS OF DAIRY CATTLE
The choice of a breed of cattle to be used in commercial dai-
ries is affected largely by the individual owner's choice, and
preference of the consumers for milk of a particular quality.
Each breed has a large proportion of desirable cows, along with
some less desirable ones.
Jerseys were introduced into the Southern states shortly after
1850 and predominate among the dairy cattle of the region.
The other dairy breeds represented are Guernsey, Holstein,
Ayrshire, Brown Swiss and Dutch Belted.
The several breeds of dairy cattle will be discussed briefly.
More detailed descriptions may be found in Farmers' Bulletin
1443, Dairy Cattle Breeds, published by the U. S. Department
of Agriculture.
AYRSHIRE
Southwestern Scotland has been noted as a dairy district for
over 175 years. The region is hilly, with considerable area de-
voted to pasture land. The climate is cool and moist in summer
and rigorous in winter. Such is the ancestral home of the Ayr-
shire, a breed whose milk long has been used in the manufacture
of fine cheese.
Ayrshires were imported into the United States in 1822.
Some Ayrshire blood was introduced into herds of range cattle
in Alachua County over 90 years ago.1 Traces of this are appar-
ent in the horns and color markings of some of the descendants
in these herds.
Ayrshires usually are inclined to be of stocky build. The color
is a mixture of white and red, sometimes shading to a rich ma-
hogany. The udders tend to be quite symmetrical and are at-
tached closely to the body. In some individuals the teats tend
to be short, though American breeders have eliminated this fault

1 Fla. Agr. Expt. Station Bul. 248. Page 10.







Florida Agricultural Experiment Stations


largely by selection of breeding stock. The horns usually are
wide spreading and tend to curve upward and outward. The
Ayrshire Digest stated that 50 percent of Ayrshire cows in the
United States are dehorned. A polled strain is increasing in
popularity.
An average herd of Ayrshires under good farm conditions
should produce from 6,500 to 9,000 pounds of milk yearly per
cow, with an average butterfat test of about 4.00 percent. The
breed average on Herd Improvement Register test during 10
recent years was 10,251 pounds of milk, 4.09 percent and 419
pounds of butterfat. Well-grown mature bulls should weigh from
1,500 to 2,000 pounds and mature cows about 1,050 pounds.
Their calves weigh from 60 to 80 pounds at birth, males aver-
aging about 5 pounds more than females. These cattle are
rugged animals and are good grazers.
BROWN SWISS
The picturesque Alps of northern and eastern Switzerland
are the native home of Brown Swiss cattle. In their native
home the cattle are housed in the valley farmsteads in the win-
ter, and some of them are moved onto mountain pastures during
the summer months. Much of their milk is used for manufac-
ture of the famous Swiss cheese. They were imported into the
United States in 1869. Because of outbreaks of foot-and-mouth
disease on the continent, quarantine regulations have restricted
shipments of livestock from Europe. Less than 200 Brown Swiss
cattle were imported and the breed has multiplied from these.
Some Brown Swiss have been brought into the Southern states.
The cows are strong and rugged, some with a tendency to-
ward coarseness as compared with more refined dairy breeds,
Mature cows weigh about 1,100 to 1,500 pounds and bulls from
1,600 to 2,000 pounds. Colors range from gray to light or dark
brown, seldom with any white marking. Horns, when allowed to
grow, are of medium size, curve outward and forward, and often
appear plain. Calves are large, many weighing 70 to 90 pounds
or more at birth.
Brown Swiss cows are considered good producers of milk
with an average richness of about 4.00 percent butterfat. Some
54,790 records of purebred Brown Swiss cows milked twice daily
for 305 days on Herd Improvement Register test yielded an
average of 9,710 pounds of milk, 4.05 percent and 393 pounds
of butterfat per year.






Dairy Cattle and Their Care


DUTCH BELTED
The Dutch Belted breed of dairy cattle is said to have some
ancestry in common with the Friesian, Oldenburg and other
breeds of cattle native to the Netherlands and the adjoining
provinces of northwestern Europe. They were owned and de-
veloped largely on estates of Holland, where they were selected
for perfection in color markings without losing sight of dairy
qualities. Their native country is a rich lowland with verdant
pasturage.
Dutch Belted cattle are black with wide white belts, which
sometimes extend sufficiently that white shows on the fore udder
and in markings on the hind feet. In common with other black
breeds of cattle, first-cross grades sometimes show an outcrop
of recessive red coloration.2 The white belt is a dominant color
marking. Cows weigh from 1,000 to 1,500 pounds, mature bulls
from 1,500 to 2,000 pounds or more. Most of the calves range
between 70 and 90 pounds at birth.
Cows of this breed are said to be slightly lower producers of
milk, but with an average butterfat test similar to that of the
Holstein breed. The average butterfat content of milk of the
Dutch Belted cows that have completed Advanced Registry tests
is about 3.8 percent. More production testing is desirable. With
good care, cows of this breed should produce above 8,500 pounds
of milk yearly.
JERSEY
Jersey cattle originated on the Island of Jersey, in the Eng-
lish Channel. These channel islands long have been famous be-
cause of the quality of milk produced by the native cows. The
fame of these cattle, and local pride in safeguarding purity of
the breed, caused the islanders to pass laws preventing introduc-
tion of any cattle for other than immediate slaughter as early
as 1789. French cattle brought by the Germans during World
War II were slaughtered by Island authorities after the sur-
render.
The first importation of Jerseys into the United States, from
which purebred cattle trace today, was made in 1850. Shortly
afterwards importations were made to New Orleans and other
Southern centers and thence became distributed widely. Be-
cause of this early introduction in considerable numbers, Jerseys
predominate in the Southeastern states.

SJournal of Heredity. 24: 283-286. 1933.






Florida Agriczltural Experiment Stations


Although a large proportion of Jerseys are solid fawn in color,
individuals vary from light cream to dark brown and black.
Admixtures of white with the other colors are common. Pigmen-
tation of the nose and tongue is more frequently dark or black,
and often the switch is black. Mature cows weigh from 800 to
1,050 pounds and bulls from 1,200 to 1,600 pounds. There is a
tendency toward selection of the larger size of Jerseys, since
the larger cows have been heavier producers on the average.
Jersey calves weigh from 40 to 60 pounds at birth. Because of
this small initial weight, they are seldom used profitably for veal.
Jersey cattle have a reputation as good grazers, ranking with
the Ayrshire breed in this characteristic.
Jersey whole milk has a yellow color and is rich in butterfat.
The average milk yield is less per cow than with other dairy
breeds, in part due to small size of animals but also because of
the high content of food solids in the milk. Some 118,233 Jersey
records on Herd Improvement Registry test in 10 years aver-
aged 7,090 pounds of milk, 5.36 percent and 379 pounds of but-
terfat per year. The milk finds favor with consumers because
of its richness and high content of milk solids.

GUERNSEY
The Guernsey breed of cattle originated on the islands of
Guernsey, Alderney, Jethro, Sark and Herm, off the coast of
France in the English Channel. These islands are intensively
cultivated and highly developed agriculturally, with dairying
as the third largest enterprise. This breed developed from an-
cestry similar to that of the Jersey breed, and resembles the
latter in some respects. Alderney was evacuated during World
War II but later the island was restocked with cattle from
Guernsey. Milk is the chief dairy product marketed on the
islands.
Guernsey cattle were introduced into America in the latter
part of the eighteenth century, along with Jerseys, under the
name of Alderney. The earliest importations to be kept pure
came in 1830. Many Guernseys have come to the South, and
rank second in numbers there among the dairy breeds.
Guernsey cattle usually are fawn and white, though some
solid fawn animals are seen. Muzzles and tongues are usually
a flesh color, with dark or smoky muzzles occurring less fre-
quently. Mature cows should weigh from 900 to 1,400 and bulls






Dairy Cattle anr Their Care


from 1,400 to 1,900 pounds. Calves usually weigh from 55 to 70
pounds, males exceeding females by about 5 pounds.
Production of Guernsey cows on Herd Improvement Register
test averaged 7,758 pounds of milk, 4.83 percent, 375 pounds of
butterfat in 305 days and 8,942 pounds of milk, 4.79 percent and
424 pounds of butterfat in 365 days. The yellow color of Guern-
sey milk has been advertised widely and finds favor with con-
sumers of bottled milk.

HOLSTEIN-FRIESIAN
The Holstein-Friesian breed has existed for centuries on the
lowlands of northwestern Europe. This area is famous for large
cattle and for the manufacture and exportation of cheese. On
the highly productive pastures, Friesian cows were bred and
developed.
Cattle from Holland were brought into New York by early
Dutch settlers long before their recognition as a breed. The
first importation to which registered cattle trace came into Mas-
sachusetts in 1861. Many were imported in the next 24 years,
and few since that time, except from Canada. Quarantine
against foot-and-mouth disease prevented importations from the
Netherlands since 1906.
The name Holstein-Friesian originated with the union of the
Holstein Breeders' Association with the Dutch Friesian Associa-
tion in this country in 1885. The term, Holstein, has come to be
the abbreviated name for this breed in America.
All registered Holsteins are black and white in color. Like
other black cattle, a few animals still carry the factor for re-
cessive red coloration,3 which crops out in the proportion of one
in four cases upon mating of animals that carry the factor for
recessive red coloration. Mature cows should weigh between
1,150 and 1,600 pounds and bulls from 1,600 to 2,400 pounds.
The calves are large at birth, usually between 75 and 105 pounds
in weight, the males being about 10 pounds heavier than females.
Because of large initial weight, many are vealed.
Holsteins thrive best where feed is plentiful. Some 319,159
records of Holstein cows on Herd Improvement Registry in 1955
averaged 11,685 pounds of milk and 429 pounds of butterfat.
Over a period of 22 years, Holsteins in the Herd Improvement
Register increased from an average of 3.37 to 3.67 percent of
butterfat in their milk. The trend has been to select herd sires

SWis. Agr. Expt. Station Bull. 313: 1-35. 1920.






12 Florida Agricultural Experiment Stations

from medium to high testing families. The milk has a pale
color, due to refraction of light from some of its colloidal con-
stituents, independent of the fat content. Holsteins are popular
in cheese and condensery districts, because of the desirable pro-
portion of casein to butterfat in their milk.

THE DAIRY HERD: SIRE AND DAM
WHAT GIVES VALUE TO A COW?
Selection of a dairy cow as the foundation of a herd should
be made with as full a knowledge as available of the following
facts:
1. Ability of the cow to produce milk and butterfat.
2. Health-freedom from tuberculosis, brucellosis, mastitis,
vibriosis, other communicable diseases and injurious parasites.
3. Condition of the cow as affected by previous feeding and
management, as well as mineral storage or state of nutrition.
4. A satisfactory breeding history, as shown by the number
of services, number of calves, date of last calving, subsequent
service record, quality of the sire by which she is with calf and
a measure of her ability to transmit dairy qualities to her off-
spring. Regular reproduction is essential to maintain high aver-
age milk production.
5. Age of the cow, since this affects the length of time that
she yet may produce and reproduce.
6. If a cow is a registered purebred, the proper registration
certificate with transfer inscribed by the breed association should
be supplied by the last owner.
7. Dairy conformation, including a good mammary system,
large feed capacity and spareness of natural fleshing. An attrac-
tive appearance of head, body and dairy character is desirable,
though beauty is less essential than is producing ability of a cow.
8. Wearing ability as indicated by a strongly attached udder,
good feet and legs and a rugged constitution. A good cow is
illustrated in Figure 3.
Total valuation of a cow is the result of the entire combina-
tion of facts listed. Serious faults in a single point may be suffi-
cient to eliminate a cow from consideration. For example, a cow
advanced in age may have little value as a potential breeding
animal.






Dairy Cattle and Their Care


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Fig. 3.-This 11-year-old Jersey cow, Florida Victor Winnie, 1060099,
dropped four male and three female calves from ten services. Although
not a show cow, she was a consistent producer, yielding 57,976 pounds of
milk and 2,694 pounds of butterfat in less than 8.5 calendar years. Sixteen
female descendants in four generations, had 37 lactations which averaged
7,708 pounds of milk, 386 pounds of butterfat. Eight younger heifers are
in the herd.

The average productive life of a dairy cow has been calcu-
lated to range between 3.5 and 6.0 years after calving the first
time. (See page 50.) This span of usefulness allows for cows
eliminated by culling, disease, accidental death, sterility or senil-
ity. Physical condition and thrift of a cow should be considered,
along with age, in making selections.

RELATION OF DAM TO PRODUCTION OF DAUGHTERS
Heredity is governed by the law of independent assortment of
genes (hereditary units). Few animals are sufficiently pure in
those hereditary units which govern milk producing capacity to
transmit this capacity uniformly to all of their progeny. This
explains in part why many good producing cows have few progeny
which equal them in producing ability, although daughters of
outstanding cows usually excel the herd average. Very high
producing cows often are exceptions in a family of medium to
good producers. Yet the hope of every breeder is to locate an
outstanding producer that may also prove to be a meritorious
transmitter on which to found a good cow family. When low-
producing cows are mated with an average purebred dairy bull,
the heifers usually are better than their dams.


r


rl



tar






Florida Agricultural Experiment Stations


An analysis of 200 pairs of dams and daughters in the Experi-
ment Station herd showed the relation existing between dams'
and daughters' production (see Table 1). The policy during
much of this time was to retain every daughter possible through
at least the first full lactation, so as to measure her transmitting
ability, however good or poor.

TABLE 1.-RELATION OF AVERAGE PRODUCTION OF DAUGHTERS TO
THEIR DAMS IN AN UNSELECTED DAIRY COW POPULATION.

Number Daughters Dams
of Pairs Milk Butterfat I Milk Butterfat
Pounds Pounds Pounds Pounds
12 4,861 247 2,683 134
14 5,320 284 3,983 183
35 5,809 295 4,598 228
49 6,140 309 5,424 274
50 5,970 309 6,301 325
23 6,623 339 7,223 375
11 6,305 324 7,763 413
6 7,085 348 8,842 468


BUILDING ON COW FAMILIES
A herd is founded on purchased cows, but the continuation
and success of this herd depends on the transmitting ability of
the individual animals. Ten foundation cows usually are re-
duced to five cow families under average conditions in 10 years.
When heifer calves are being raised as replacements, the herd
records should be studied and those calves from good and me-
dium producing cows and from good cow families within the
herd selected. Success in breeding dairy cattle depends on con-
tinuous study of records to eliminate undesirable animals, and
to locate and multiply desirable families.
Between 1901 and 1948, 39 registered Jersey females were
obtained for the Experiment Station dairy herd. Some cows or
their descendants were removed because of low production, poor
transmitting ability, lack of female progeny, disease or other
causes. Seventeen still were represented by progeny, including
six of the original females purchased since 1942. Early culling
was based on individuals, but elimination of poorer families has






Dairy Cattle and Their Care


been practiced also. An analysis of three good and two poor
families, when every heifer calf was saved to be raised, was
as follows:

Founda- Genera- Descend- i Number
tion tions of ants with of Average Butterfat
Female Progeny Records Lactations Milk Production
Pounds Pounds
A 3 5 21 6,497 344
B 4 9 32 6,455 330
C 4 12 50 6,261 326
D 5 21 62 5,319 273
E 4 10 37 5,060 260


Based on the information from Table 1 and a similar study
of 2,165 daughter-dam pairs of cows in Dairy Herd Improvement
Associations by J. C. McDowell,4 the recommendation can be
made to select heifer calves out of the medium and higher pro-
ducing cows. A few exceptional animals will be discarded among
the calves from low-producing cows, but the majority from low
producers will have below average milk and butterfat production.
A further example will demonstrate differences in ability be-
tween cow families. Cows number 213 and 225 entered the Sta-
tion herd in 1924, and appeared about equally desirable for foun-
dation purposes. Their progeny were by the herd sires used
during this period.
Cow 213 was the ancestor of 19 female descendants in five
generations which produced an average of 5,618 pounds of milk
in 48 lactations. In the same period, 24 descendants of Cow 225
in five generations averaged 7,799 pounds of milk in 70 lactations.
There was a striking difference between these two families in
each of the five generations.

SELECTION OF A HERD SIRE
The selection of a herd sire is the most important decision
made by a dairyman, since five to eight years hence a large pro-
portion of the milking cows may be progeny of this animal.
Since it is so important to the dairyman who raises replacements,
how can the chances of selecting a good bull be increased?

U. S. Dept. Agr. Dept. Circ. 368: 1-14. 1926.






Florida Agricultural Experiment Stations


There is no way of selecting a young dairy bull with assur-
ance that he will transmit high production to the major propor-
tion of his progeny. Young untried sires are used always with
the knowledge that the offspring may not prove wholly satisfac-
tory. Copeland 5 found the most satisfactory method of obtain-
ing a herd sire was to select a good proved bull, when available,
or a son of a good proved bull, out of a cow with good daughters
and 10 or more good paternal half-sisters.
Careful scrutiny of the conditions of proving a sire includes
studying the dams and daughters, environment and manage-
ment while under test and actual production records of both
dams and daughters. Computed averages sometimes may be
misleading, unless all conditions are considered. Bull indexes
are merely guides. They are based upon an assumption that pro-
duction of a cow also measures her transmitting ability-which
too frequently is incorrect.
Questions to consider when selecting a young bull are:
1. Has his sire transmitted high producing ability to a large
proportion of his daughters? Do the paternal sisters equal or
excel their dams in average milk and butterfat production ? Were
production records of dams and daughters made under similar
conditions of feeding and management?
2. Has the dam been a satisfactory producer year after
year? Does she have sisters her equal, or is she a high producing
freak in a mediocre family? Does she have the constitution,
capacity and mammary development desired? Is she better than
cows in the herd where the bull will be used. Has she transmit-
ted producing ability and desirable conformation to her other
progeny?
3. Does the bull have desirable conformation, including good
depth and circumference of chest, length of body, depth of ribs,
length of rump, desirable placement of rudimentary teats, good
size for age, spareness of fleshing inside the thighs and a general
appearance of dairy temperament? These characteristics denote
constitution, capacity for feed, dairy temperament and mammary
development. Health of the animal and of the herd from which
he comes are essential. Is he free from known hereditary de-
fects? An example of a good proved bull is shown in Figure 4.
Only good purebred dairy bulls should be used. Large num-
bers of Dairy Herd Improvement Association records analyzed
by the Bureau of Dairy Industry, U. S. Department of Agricul-
SJournal of Dairy Science. 17: 93-102. 1934.






Dairy Cattle and Their Care


ture, have shown that purebred dairy cows usually exceed grade
cows in producing ability. The desirable qualities of good grade
cows have come in large part from their purebred ancestors.
Some 30 percent of the dairy cows in the United States have
been bred artificially and such service is available in a large part
of the country. Desirably proved bulls are used most extensive-
ly. Many selected young bulls are being sampled under artificial
service. Committees have studied the background of each bull
selected for use by the artificial breeding organizations. The
dairyman himself also should decide from among those bulls
available which ones he wishes to use with his herd.
Extended fresh semen usually is transported at a tempera-
ture little above freezing and used within 48 hours. After that
time unused semen is discarded as useless. Semen is frozen,
stored, and transported by two different methods in special equip-

Fig. 4.-The herd sire transmits one-half of the characters inherited
by his daughters. The quality of his immediate ancestors, individuality of
the bull himself and the characteristics of all known progeny should be con-
sidered prior to his purchase. Sophie 19th's Victor 81st 331031 was from
good parents. He possessed good breed character, constitution, capacity
and general conformation. His 67 daughters averaged 6,374 pounds of milk,
321 pounds of butterfat per lactation. Thirty-four sons were used in Florida
herds. Most of his daughters and granddaughters were desirable cows.
Such an animal merits continued use throughout his lifetime.

IEgM---M--i. F ''^ ^






Florida Agricultural Experiment Stations


ment which maintains it at -110 or -320 Fahrenheit. The
ampules of this semen are thawed in ice water at time of use.
CARE AND MANAGEMENT OF THE BULL
Progress in improvement of a dairy herd depends to a large
extent upon transmitting ability of the herd sire. Hence it is
important that his ability be proved while yet living. He is the
most important animal in the herd, contributing one-half of the
inheritance to all progeny. If a good proportion of his daughters
excel their dams in producing ability, he is a valuable animal
worthy of use as long as he is serviceable.
Since bulls often become dangerous suddenly, special provi-
sion should be made for safe care and good management. A
GENTLE BULL NEVER SHOULD BE TRUSTED; A TEM-
PERAMENTAL BULL WILL NOT BE.
How can a bull be maintained safely, and as a satisfactory
breeder? While still young, a bull should have a light copper
ring inserted high in the septum of the nose. This light ring
should be replaced with a heavy bronze cannon-metal ring when
the animal is two or three years old. He should be trained to lead
while he is young and tractable. Bulls always should be handled
firmly; never petted or teased. The gentle bull is often the most
dangerous.
Opinions differ as to whether or not to dehorn bulls. They
may be dehorned while very young. Some persons prefer to let
the horns grow for several months and then perform the opera-
tion during cool weather. Some think the latter method makes
the bull more cautious in the aggressive use of his head. If
the horns are allowed to remain, it is sometimes desirable to
round off the tips, so that he is less likely to injure other animals.
A separate paddock, pasture or exercise lot, adjacent to a
shelter and to a safety breeding chute (see Fig. 5), has proved
satisfactory for handling and housing bulls. Where two or more
bulls are kept, each may occupy a small shelter pen provided
with feed, water, mineral supplement and access to a large pad-
dock. A long narrow paddock one-half acre or larger in size,
from which a bull can see out, is more conducive to exercise than
a square pen. A low amperage electric fence often is useful. The
design should be one approved by the National Insurance Under-
writers Association. CONTINUOUS CURRENT NEVER
SHOULD BE USED.
Sometimes two congenial bulls may occupy the same pad-
dock, although there is risk of injury. Some type of paddock is







Dairy Cattle and Their Care


necessary because, without exercise, bulls get sluggish and are
less effective in service.
The feeds supplied to a bull should be of good quality and
enough to keep him in a vigorous thrifty condition, but not fat.
The quantity of forage
Fig. 5.-A safety breeding chute can be should be limited some-
constructed in the corner of any paddock. The
gate swings inward to admit, and remove, the what, to avoid making
cow without the attendant having to enter the bull paunchy or
the bull's pen.
the bull's peheavy in the middle.
S] Good grazing and exer-
cise may be provided in
a strongly-fenced pas-
.eedun ture separate from the
se dairy herd. Good le-
gume forage, with an
allowance of green pas-
Ball. ture or soiling crops, is
desirable. Silage may
be fed in limited
r amounts. Shade and
S-water should be avail-
*ga able always.
I Bulls require only a
/ limited amount of con-
// centrates. The concentrates need not contain
over 16 percent total crude protein, and may be
S made up of such feeds as wheat bran, corn feed
/ meal, oats and cottonseed and linseed oil-meals.
It is desirable to give bulls access to common salt
/ and such mineral matter as is needed on the local
soil areas. Too much feed and too limited exer-
cise shorten the useful life of many bulls.
Feet and legs require regular attention. Hoofs
that do not wear evenly should be trimmed to
allow normal posture. Too many bulls are elim-
inated for lameness, being stifled, or inability
to mount, because of neglect of hoofs.
Studies at the South Carolina Station showed
that dairy bulls were more effective in natural
service when used not oftener than 12 times per month. Arti-
ficial breeding units have found one semen collection per week
satisfactory, and some vigorous bulls may be used as often as
twice a week. With bulls under two or over eight years of age,







Florida Agricultural Experiment Stations


somewhat lighter service is desirable. Breeding efficiency was
lower in herds with cows showing any abnormal vaginal dis-
charge. Barring accidents, the average good dairy bull may be
expected, with good care, to remain serviceable past 10 years of
age. Although many bulls are disposed of younger, a small num-
ber have been useful even until 19 years old.
Failure of cows to conceive at first service often has been an
erroneous reason for discarding a good bull. A large number of
records were assembled from published literature and from the
Florida Station herd relative to breeding efficiency in cattle. Of
4,819 pregnancies tabulated, 62 percent conceived at the first
service, 19 percent at the second service, and nine percent at the
third service. A few instances of conception beyond the tenth
service were noted. The records showed that two services per
conception were not unusual. In eight experiment station herd
reports studied, an average of 1.78 natural services were re-
quired per conception.
At the Florida Station 62 percent of the calvings studied
followed a single service, 22 percent after the second service and
7 percent from the third service. Five extreme instances out of
1,000 conceptions between 1922 and 1947 were from the 9th to
14th services. Heifers at the Ohio Station conceived slightly
more readily than did older cows among a group of 340 Jersey
and 379 Holstein pregnancies. The Nebraska Station analysed
their records for a period of longer than 30 years and found
under their conditions that 24 percent more services were re-
quired for heifers under two years of age than for cows. It has
been observed at the Florida Station and in certain other areas
that the state of nutrition (total nutrients, minerals, protein,
vitamin A) is a factor affecting the regularity of estrum in cows
and heifers. State of health of the reproductive organs also
affects the readiness of conception.
Analyses of breeding records of cows in the Florida Station
dairy herd from 1932 to 1948 have been made relative to concep-
tions obtained during the various months. Generally, fewer
services per conception were required during spring (March,
April and May), when young grass was plentiful. In autumn
(September and October) the most services were required per
conception. Since the market demand for milk is greatest during
the winter periods in most parts of Florida, many dairymen try
to have more of their cows freshen in time for the heaviest pro-
duction at that season. Conception to services during November







Dairy Cattle and Their Care


through February was equal to the average of the year (see
Table 2). Adequacy of good green forage may be concerned in
seasonal conception rate, hence the desirability of improved fer-
tilized pastures for use with dairy herds.
Good management of a dairy herd requires that breeding rec-
ords be kept. The service dates may be listed consecutively in a
notebook and then recorded in a small herd book on the separate
record of each cow. A record of estrus dates permits a herdsman
to anticipate probable next estrum. Conception rate was high-
est on service late in the heat period.

SAMPLING AND PROVING THE SIRE
Young bulls, selected with the best judgment, must be proved
before too great dependence is placed on their use. The cost of
raising heifers is so great and the chances of their turning out
satisfactory is so variable that it is good business to sample
junior herd sires before placing them in heavy and continuous
use. The better practice is to breed junior sires to a group of
heifers pending the arrival of 10 to 15 heifer calves, a number
which Copeland 6 found sufficient to get a reasonable measure on
transmitting ability. The junior sire then may be held in re-
serve or used where heifer calves are of less importance until
the heifers come into production. His feed bill from two to 41/
years of age is much less than the loss incurred should most of
his female progeny prove undesirable. In the meantime, older
cows and heifers from the most promising families within the
herd are reserved for the proved senior herd sire. Once a junior
sire has proved satisfactory, there is plenty of time to use him
extensively with the good cows from which all heifer calves are
to be retained. The results of proving seven Jersey bulls in the
Station herd are as shown in Table 3.
What information comes from proving bulls? This can be
seen by referring to Table 3. Bulls A, B and F decreased milk
yield of their daughters. The average butterfat tests were in-
creased by bulls B, D and E. The daughters of bulls C, D, E and
G produced more milk and butterfat per year than did their dams.
Bulls C, E and G truly were herd builders. Bull D was a valu-
able sire in that his daughters were able to maintain satisfactory
milk production and to increase butterfat yield, even when these
daughters were out of good producing cows. Bull A did not
justify being in a commercial dairy herd, while bulls B and F
Copeland L. The Jersey Bulletin and Dairy World 51: 7-8, 28, 30-32
January 6, 1932.








Florida Agricultural Experiment Stations


TABLE 2.-EFFECT OF SEASON ON BREEDING EFFICIENCY.


Month


January ........
February ......
March .......
April ...........
M ay ............
June .............
July ..............
August .......
September
October ......
November ....
December ....


1,839


Season

Nov.-Feb .... 628
March-May .. 495
June-Aug ... 458
Sept.-Oct. ... 258


1,839


Total Number
Services Conceived

155 76
163 74
161 79
163 78
171 78
146 74
150 65
162 70
130 58
128 51
120 51
190 86


Number
Not P
Conceived Co

79
89
82
85
93
72
85
92
72
77
69
104


999


999


TABLE 3.-PERFORMANCE OF DAUGHTERS OF SEVEN JERSEY BULLS AS
COMPARED WITH THEIR DAMS.
Proportion of
Daughter- Increase or Decrease in Daughters Increase
Sire Dam Production of Daughters Over Dams
Pairs Milk ] Test Fat [ Milk Fat
Lbs. % Lbs. % %

A 13 561 -.16 32 46 46

B 8 -2885 +.22 -134 13 13

C 67 + 962 -.25 + 35 70 58

D 32 + 106 +.07 + 10 44 53

E 17 + 678 +.10 + 29 53 47

F 5 -1804 -.30 -110 0 0

G 13 +1433 -.18 + 65 77 77


I Services
percent Per
nceived Conception

49.0 2.0
45.5 2.2
49.1 2.0
47.9 2.0
45.6 2.2
50.7 2.0
43.3 2.3
43.3 2.3
44.6 2.2
39.8 2.5
42.5 2.4
45.3 2.2


45.7 2.2




45.7 2.2
47.5 2.1
45.6 2.2
42.2 2.4


45.7 2.2







Dairy Cattle and Their Care


transmitted extremely low production to their daughters. For-
tunately, the poor transmitting ability of Bulls B and F was
determined early and these animals were butchered before they
sired many heifers.
What proportion of dairy bulls prove satisfactory? Records
of 4,289 bulls of five dairy breeds were accessible in USDA Agri-
culture Handbook No. 7, in 1950. Analysis of these production
records in dairy herds under DHIA test over the country showed
that the majority of herd sires tended to increase production
of their daughters from low-producing cows. With herds aver-
aging 300 to 400 pounds of butterfat, about one-half of the sires
had increased or at least maintained producing ability of their
daughters. Fewer bulls increased production of daughters from
cows yielding above 450 pounds of butterfat. It was assumed
that more than average consideration was given to the selection
of bulls for these herds. The analysis of these records is shown
in Table 4.
LENGTH OF USEFUL SERVICE
How long can a desirable proved bull be used in natural serv-
ice under good care and management?
A nation-wide survey of dairy bulls allowed to live out their
period of natural service provided an answer. Since a bull is five
years or older by the time his daughters can be proved satisfac-
tory producers, only the records of bulls past that age and born
prior to January 1941 were used. The average useful life span
and anticipated usefulness of bulls in natural service at different
ages is presented in Table 5.
As shown in Table 5, these 4,773 five-year-old dairy bulls
lived to an average age of 10.24 years at last effective service.
In other words, they still had 5.24 years (10.24-5.00) of usefulness
ahead on their fifth birthday. Of that total number, 55 percent
still were in active service on their tenth birthdays and were
useful for an additional 2.22 years on the average. Those bulls
still fertile on their fifteenth birthdays amount to 3.0 percent
of the original group, and yet were effective for a little over a
year. Beyond this age more than one-half of these animals
passed out of service in each succeeding year, so the forecast
of their future usefulness is highly uncertain.

NATURAL CAUSES OF TERMINATION OF USEFULNESS
Some 5,731 records of dairy bulls eliminated from service by
natural causes have been analyzed to base recommendations for








Florida Agricultural Experiment Stations


TABLE 4.-INFLUENCE OF 4,289 BULLS OF FIVE DAIRY BREEDS ON BUTTERFAT
PRODUCTION OF DAUGHTERS AS COMPARED WITH THEIR DAMS.*


Range of I
Average Influence of Bulls on Daughter's
Fat of Damns Increased Maintained**
pounds number percent number percent

575
and above -
550-575 5 29 1 6


525-550
500- 525
475-500
450 475
425-450
400- 425
375- 400
350-375
325- 350
300- 325
275- 300
250-275
Below 250


6
27
59
104
195
284
342
320
279
124
79
24
10


21
35
32
30
36
39
43
47
56
56
72
69
63


Fat Production
S Decreased
number percent


6
11
19
44
109
172
243
307
313
216
148
50
18
6
2


Total 1,858 767 1,66

Percentage 43 18 3


4

9


Analyzed from records reported in UT.S.D.A. Agriculture Handbook No. 7, 1950.
** A bull was considered to maintain production if records of daughters and dams varied
10 pounds or less in butterfat.


TABLE 5.-AVERAGE USEFUL LIFE SPAN AND ANTICIPATED USEFULNESS IN
NATURAL SERVICE OF DAIRY BULLS AT DIFFERENT AGES.*


Number of Propor
Age Bulls Total I


Years Per

5 4,773 10(
6 4,476 94
7 4,121 8(
8 3,689 77
9 3,181 67
10 2,616 55
11 1,922 4(
12 1,283 27
13 745 16
14 363 8
15 146
16 63 1
17 24
18 8
19 3

Bulls born prior to January 1941.
** Too few numbers to be significant.


tion of Average Age Anticipated
lumber at Last Effec- Usefulness at
tive Service Different Ages


cent











.32
.50
.17
.06
.06


Years

10.24
10.55
10.90
11.29
11.73
12.22
12.83
13.50
14.26
15.12
16.13
16.99
17.86
18.80
19.26


Years

5.24
4.55
3.90
3.29
2.73
2.22
1.83
1.50
1.26
1.12
1.13**
.99**
.86**
.80**
.26**








Dairy Cattle and Their Care


extension of the useful life of such animals. The causes which
terminated service of this group are set forth in Table 6.

TABLE 6.-CAUSES OF ELIMINATION OF DESIRABLE DAIRY BULLS FROM
SERVICE AT TERMINATION OF NATURAL USEFULNESS.


Reasons for Disposal

Reproductive
Sterility and defects of reproductive organs
Low breeding efficiency, inability to breed.
Reproductive organs infected .........................
Sub-total ...... ........ ...... ......................
Physical Reasons
Accidents and injuries ................................
Old age ............................................... .........
Feet and legs, crippled, lameness,
arthritis, rheumatism, infected feet ..
Foreign bodies ................................................
Paralysis, spinal troubles ...... .........
Rupture, crampy, slow, poor
physical condition ..--................................
M miscellaneous ....................................... ........
Poisons ....................... ....... ............. ......... .... ......
Hereditary defects ....---.......................................
Sub-total ............. .............- ....... .........

Diseases Generally
Brucellosis, Johne's disease, tuberculosis ......
Digestive diseases, bloat, intestinal twist ....
Lump jaw ....................................-.....
Tumors, abscesses, liver infections ..............
Trichomoniasis, vibriosis ........................
Pus infections ........................-.. ......---.... ..-...
Kidney and urinary conditions ......................
Pneumonia, pleurisy, lung adhesions ..........
Heart trouble ......................................... ......
Miscellaneous infections and diseases ..........
Blood vessel rupture .................- .........
Cancer, leukemia ...- --- ..-......... ...
Died, but cause not diagnosed ....................
Sub-total ........................ ...------............--


Total Bulls .......... .......-........ .-- -..-- .........


Number of
Bulls


1,604
502
54



558
523

297
291
81
22
22
16
13



225
221
194
97
81
76
58
94
31
20
16
4
631


2,160












1,823


1,748


5,731


Percentage
of Total





37.69












31.81














30.50


100.00


The onset of sterility, which terminated the usefulness of 28
percent of the bulls studied, may be delayed in some instances.
A number of causes may be involved-improper feeding, insuffi-
cient exercise, excessive use, injuries in handling or shipment,
and pathological conditions.







Florida Agricultural Experiment Stations


Lameness, poor feet and legs, and accidents on slippery floors
sometimes may be prevented by use of sand or cinders. These
also aid in wearing the hoofs to keep the feet in good condition.
Hoofs need regular attention and trimming when necessary.
Autopsies showed 5.1 percent of these dairy bulls had died
from injuries due to swallowing metal objects (wire, nails, staples
and similar material). An electromagnet at the feed mixer and
careful disposal of all baling wire may reduce this danger.
Miscellaneous non-infectious causes of loss included licking
lead paint, eating poisonous plants and bloat. Some of these
are preventable.
Infectious causes accounted for about 30 percent of the
losses of dairy bulls. Campaigns of detection and elimination
have reduced tuberculosis and brucellosis. Lump jaw, caused
by a fungus, can be corrected medically or removed surgically,
if recognized and treated in time. New cases can be reduced
by thorough disinfection of yards, feed mangers, drinking facili-
ties and places where the infection can be spread by rubbing.
This fungus can be communicated to man, and must be handled
with care.
Many bulls died without diagnoses or autopsies. Knowledge
of causes of these deaths might have aided in care and manage-
ment of other animals.
No bull can be expected to live forever but good feeding,
management, care and sanitation can extend the useful life span
of many valuable animals. Observation and timely veterinary
care have prolonged the life of many animals.

BREEDING RECORDS
Breeding records are necessary to manage a dairy herd.
Identification of each cow is required for cows inseminated by
technicians representing artificial breeding organizations. The
registration certificate must be available for identification of
purebreds if the offspring is to be eligible for registry.
Breeding records should be kept consecutively on a barn record
or in a breeding diary or notebook, as shown in Figure 6, and also
on each cow's individual record, as in Figure 7. One may obtain
quickly from such records a consecutive list of the cows expected
to calve, and know when they should be turned dry so as to allow
four to eight weeks before the next calving. A "barn breeding
record" sheet is available through the Agricultural Extension
Service.







Dairy Cattle and Their Care


Knowing when the calf may be expected, arrangement may
be made to separate the cow and give her closer attention about
calving time. These records may call attention to the need for
veterinary treatment or correction of breeding irregularities.

Service Sex Calf
Cow Date Bull Due Calved Sex Number
894 11-10-55 Esmond 8-14-56 F 152 X
658 11-11-55 Pioneer 8-17-56 M 153 X
517 11-11-55 Pioneer rebred
141 11-11-55 Squawlock Irebred
141 12- 4-55 Marksman sold for beef 2-12-56
517 12- 6-55 Sultan 9-8-56 F 154 X (dead)
650 12-27-55 Signal 10-5-56
825 1- 2-56 Advancer 10-11-55


Fig. 6.-A breeding diary shows dates, animals concerned, expected
calving date, identity of progeny and disposal of animals. (Artificial in-
semination was practiced.) Any bound notebook can have the headings
written at the top of each page and become a permanent record for use in
management of the herd.

Many kinds of herd books and record systems are available.
A compact loose-leaf record book, devised at the Oklahoma Sta-
tion, contains much of the information desired in a record sys-
tem. It includes name and date of birth of the animal, provi-
sion for identification by color marks, tattoo or herd number, a
brief pedigree, and the complete reproduction record on the face
of the looseleaf form. The reverse side of this form has spaces
for four lactation records, as long as 14 months' duration (see
Fig. 7). Retail dairymen may wish only milk records. Others
may wish to use the butterfat tests on each cow at monthly or
bi-monthly intervals, so that feed may be allowed in proportion
to butterfat production. The total milk yields for each month
are taken from the monthly milk sheet kept at the dairy barn,
by weights recorded either daily, once weekly or three times a
month or computed from a single day's weight at the middle of
each month. Daily milk weights require slightly more work to
obtain but allow a dairyman to watch any irregularity in the
condition of the cows as seen by variations in production from
day to day.






Florida Agricultural Experiment Stations


O 0
N ...Florid. Onyx an-ce


0
.S.: 6-7-- Jy .. l t1 S


836 F
9 56
II FAT MONTH


T MONTH


MiLKi % FATI MONT


1 MILK


OtqW I1 -11 A1 11


Nov 850i .s ov 104' t9y 1153: I
-Ac C 9.q& 5C S5OE Dc. 11 187 5. SW


Jrt8406' 8 1-'-7 Jan 101'_ 5-" 57.

omr 8t 6O P r 84Q' 6!0so5 _o
B.p 780:'f2 f5 .A r 82~ 54S.
8M% 332!4 4.S u 845 8______ 8
___ne 852 7 ___________ ____t
JU1y 725- S'3 JuV -148. SA
g 506:.s. AuY 43.' 44!-



Fig. 7.-The loose-leaf herdbook form allows for identification, short
pedigree and reproduction records on one side and four yearly production
records on the other. Dates of calving and first and last milkings are
shown for each lactation.


sS(
11 O1
MONTH MiLK
Oct 993


. .. .. "~


% FA






Dairy Cattle and Their Care


KEEPING DAIRY RECORDS
Good management of dairy herds centers around a simple
system of herd records so that a dairyman can know, without
question, all essential facts concerning each cow. Any good sys-
tem of records should be sufficiently complete that, upon absence
of the owner or manager, another person can take records and
determine the following facts regarding any animal in the herd:
1. Identification of each animal by color markings, ear tattoo,
tag or neck strap number.
2. Sire and dam of each animal if known.
3. Age of the animal.
4. Breeding record up to date.
5. Production record up to date.

COOPERATIVE RECORD SYSTEMS
Nearly 1,500,000 cows were on the standard Dairy Herd Im-
proved Association (DHIA) record plan in the United States in
January 1957. Over 400,000 cows were on the owner-sampler
plan of production records. A weigh-a-day-a-month plan which
involves milk weights of each cow and feed consumption by the
herd was introduced in September 1956. Under all three pro-
grams combined, records were being kept on nearly 2,000,000
cows in 63,590 herds. A large proportion of these records were
in commercial herds.
The DHIA plan was the most popular and complete of these
record systems. It included milk yields, monthly butterfat tests,
estimates of feed consumption, total income, returns above feed
costs and other pertinent information on each cow in the herd.
DHIA records secured under uniform supervision have been ap-
proved and published by several breed associations. Use of these
records enables dairymen to feed individual cows more econom-
ically. They point out the cows that were profitable, and from
which to save heifer calves. The lower producing and unprofit-
able cows are identified for subsequent disposal. The records
also furnish the basis for other good management practices and
give a definite knowledge of income and return. Many bulls
used by artificial breeding organizations and in purebred herds
have been located from among sires "proved" through produc-
tion of their daughters under DHIA supervision.
The owner-sampler and weigh-a-day-a-month plan (WADAM)
were designed for benefit of the herd owner in feeding, culling
and some phases of herd management. Owner-sampler records






Florida Agricultural Experiment Stations


are based on private milk weights, and milk samples analyzed
for butterfat percentage at a central laboratory. The WADAM
plan is based on one day's milk weights for each cow and feed
statements for the herd kept by the owner, computed at a small
fee in a central office in the county. The cost is low and less de-
tailed information is obtained than with the DHIA. However,
the owner-sampler and WADAM methods are good ways to be-
gin keeping production records.

RAISING HERD REPLACEMENTS
DAIRY CALVES
The annual replacement of cows in dairy herds ranges from
20 to 50 percent, depending on the source of herd replacements.
High producing cows are high priced, while lower priced cows
often are undesirable. Average depreciation rates are higher
in herds maintained by purchased replacements than in herds
raising calves. Calves sired by a bull of proven transmitting
ability and out of the better cows in the herd may develop into
high-producing milk cows. Danger of introducing diseases and
parasites into a herd is reduced when home-raised calves are
the source of replacements.
Natural increase in the size of a dairy herd through home-
grown replacements proceeds slowly. Limiting factors are the
productive life span of dairy cows, intervals between calvings,
ratio of female to male calves, death losses and reproductive
troubles. Complete life histories of 249 Jersey cows in the Station
herd were studied. An average of 1.86 full-term heifer calves
were dropped per cow. Losses of calves and heifers from all
causes left an average of 1.21 females per cow to enter the
milking herd. If a herd is to be maintained at the same numbers,
one would need to plan on saving the living heifer calves from
the better 80 percent of cows in the herd. Two such Florida-
raised heifers are shown in Figure 8.

THE CALF AT BIRTH
The calf should be born in clean, dry surroundings. A clean
grassy lot or small pasture having shade or shelter, and apart
from other animals, is desirable as a maternity lot. The ma-
ternity lot or stall should be located where the cows will be seen
several times daily. An attendant then will be near to assist
during calving if necessary. Lots in which many animals are
kept should be avoided.







Dairy Cattle and Their Care 31

The calf's navel should be disinfected soon after birth so as
to eliminate infection or screwworm infestation and to heal the
navel cord. Calves given a good start on colostrum the first three
days of life are likely to develop into thrifty, vigorous animals.

FEEDING METHODS FOR DAIRY CALVES
TAKING THE CALF FROM THE COW
Many herdsmen separate the cow from the calf when it is
less than 24 hours old, believing that less family attachment
will develop between mother and baby. Usually both cow and
calf get along better when separated early, the cow soon becoming

Fig. 8.-This young cow supplied the family of a 4-H Club member with
milk. She was bred artificially to a proved sire. Her calf is learning to
drink from a nipple bucket, and promises to become a splendid herd re-
placement.






Florida Agricultural Experiment Stations


accustomed to the barn routine and the calf learning to drink
milk.
COLOSTRUM AS CALF FEED
Colostrum, or the first milk produced by the cow after calving,
is of special benefit to the new-born calf. It is rich in vitamins,
is laxative, starts the digestive tract functioning properly and
contains bacterial anti-bodies which help to combat common in-
fections. Without colostrum, survival is difficult. Many cows
produce more colostrum than can be used by their own calves.
It may be saved in frozen storage for emergency feeding of calves
whose dams do not supply a sufficient amount, or to modify skim-
milk for feeding others.

RAISING CALVES ON NURSE COWS
Some Florida dairymen and owners of family cows place
calves with nurse cows. A good nurse cow sometimes will supply
milk for two or more calves at a time. Some dairymen replace
the older calves with young calves after several months, de-
pending on quantity of milk and the supplementary feed available
for the older calves. This is an expensive method when there is a
market for whole milk, but has been a means of starting calves
off well before they can subsist wholly on other feeds.

THE NIPPLE BUCKET
The young calf, nursing normally, has its head extended and
gets milk in a small stream, which passes directly to the fourth
compartment of the stomach. The bucket-fed calf has its head
down and swallows in large gulps which tend to allow milk to
enter the first compartment of the stomach. Any milk getting
into the first compartment putrefies, causing indigestion, diarrhea
and unthriftiness.
Buckets or pails with detachable nipples are designed to
hang on the pen or fence. The nipple has a small opening and
simple valve which allow only a small amount of milk to pass at a
time and closely simulates the conditions of normal nursing.
After each feeding, nipples and valves should be taken apart,
cleaned and sterilized. Nipples should be replaced frequently,
since the openings in them become enlarged after long use and
allow milk to pass too freely, defeating the intended purpose.
Calves raised on clean nipple buckets tend to have little digestive
trouble. Strict sanitation and good management are still neces-
sary. Nipple pails are available from dairy supply companies.







Dairy Cattle and Their Care


FEEDING WHOLE MILK AND SKIMMILK
Calves need about 1 pound of whole milk for each 10 pounds
of live weight daily. A 50-pound Jersey heifer calf can be fed
21/2 pounds of whole milk morning and evening. The amount
of milk may be increased in proportion to the gain in body weight,
at the rate mentioned above.
This is an expensive method in market milk areas. Prior to
World War II many calves received whole milk for the first six
weeks; then skimmilk until about six months of age. This prac-
tice has largely gone out of use, since less separated skimmilk is
available on farms, and market milk has a Class I value.
Whole milk may be replaced by equal parts of colostrum
and reconstituted skimmilk, in addition to leafy forage and dry
concentrates.
When whole milk is scarce or high in price the change to
skimmilk and colostrum may be made at three weeks of age.
Reconstituted skimmilk may be made up by using a ratio of 1
pound of powdered skimmilk or powdered sweet buttermilk to
9 pounds of warm water and fed at about body temperature.
This reconstituted skimmilk may be fed at the same rate as fresh
skimmilk. Calves always should be fed under sanitary conditions
and in clean buckets.

LIMITED MILK FEEDING-DRY METHOD
A number of calf meals are on the market for raising calves
when milk is scarce or high in price. These meals have proved
satisfactory when 200 to 350 pounds of whole milk have been
fed during the first six weeks of the calf's life to insure a proper
start. The meals contain an appreciable percentage of high
quality animal protein (dried milk products, soluble blood flour,
fishmeal, etc.) and are adequate for raising thrifty calves when
used with high quality leafy hay and vitamin supplements. At
10 to 16 weeks of age or possibly earlier, a simple grain mixture
may be fed with good hay or pasture. Some calves raised this
way tend to have rough hair and be slightly under-developed
when six months of age, but if properly fed and cared for be-
tween six and 15 months of age, they will attain normal size and
weight by breeding age.

LIQUID MILK SUBSTITUTES AND GRUELS
Several substitutes for whole milk containing dried milk by-
products are on the market. They are used in place of liquid







Florida Agricultural Experiment Stations


milk after colostrum feeding and are fed as gruels early in the
calf's life. Later they may be fed dry if desired. Considerable
time is involved in preparing gruels, and extreme care should be
exercised in cleaning and sterilizing the utensils and buckets.
These products differ in formula and should be fed according to
the manufacturer's directions.
Calves vary in the age at which they start to eat dry grain.
The majority begin when less than two weeks old; others later.
By the third week a Jersey calf will eat about one-fourth to one-
third of a pound of concentrates daily. They may be offered up to
one pound of supplementary dry grains before six weeks of age.
The offering to older calves should be limited according to growth
and development, not exceeding three to four pounds daily at
any age.
Concentrates for calves under six months old may consist of
a mixture of whole grains. Whole grains are more palatable
than ground grains.
High grade fitting feed, which contains cracked or crimped
grains, alfalfa-and-molasses and an oilmeal, is also a good con-
centrate for young calves. Mixed dairy feeds may be reduced to
12 percent total crude protein by addition of citrus pulp and
shelled corn or corn feed meal. After the calf is six months old
the grains should be ground.

LEAFY FORAGES
Calves will take some leafy forage when a few days old and
the amount should be increased as the digestive system develops.
This may be offered in amounts that will be eaten daily. Hay
consumption often starts in small amounts by the second or third
week and may increase to more than one pound daily by eight
weeks of age. Thereafter leafy forage may be offered in as
large amounts as the animal will consume. This forage may be
fresh pasture or early-cut hay.

PRECAUTIONS IN CALF MANAGEMENT
Always weigh or measure milk in proportion to weight of the
calf. A Jersey calf at birth needs about one to one and one-half
quarts of milk per feeding. The milk should be fed at body tem-
perature and at 12-hour intervals. Over-feeding or sudden
changes often upset the digestive system. At the first sign of
digestive upset, milk should be reduced until the animal re-
covers.







Dairy Cattle and Their Care


Fresh clean water and a limited allowance of leafy hay should
be available continually. All feeding utensils, pens and yards
need to be kept clean.
A good calf man knows each individual animal and watches
all of them closely. The success of raising calves depends largely
upon his interest and skill in caring for each individual animal
regularly and carefully according to its needs.

HOUSING FOR CALVES
Calves need to be sheltered in clean dry surroundings. Ade-
quate ventilation with freedom from direct drafts aids in pre-
venting cases of colds and pneumonia. If newborn calves are
penned separately or tied, less chance is afforded for spread of
disease or parasites. Also separate pens lessen the opportunity
for sucking and possible injury of udders. Individual stalls also
assure that each calf can have access to his own allowance of
feed.
Calves prefer to lie on a wood platform or on clean bedding
rather than on bare concrete floors. Various materials that are

Fig. 9.-Individual portable calf pens prevent calves from injuring
udders by sucking one another, reduce spread of diseases and aid in para-
site control.







Florida Agricultural Experiment Stations


clean, dry and absorbent, such as peanut shells, straw, wood
shavings, etc., have been used satisfactorily.
Individual portable calf pens, similar to Figure 9, are less
expensive than a permanent calf barn. They have been satisfac-
tory when moved frequently onto clean well-drained ground.
Such separate pens are useful so long as calves are receiving
liquid milk as feed.

FEED FROM WEANING TO BREEDING AGE
Calves usually are considered old enough to wean from milk
products at 60 to 80 days of age, depending on thriftiness, though
if surplus milk is on hand its use may be continued. Good pas-
ture and a good grade of dry forage, silage and mineral supple-
ment may make up the major portion of the feed for growing
heifers. Mineral supplements are essential, particularly where
the pastures and roughages are grown on certain light sandy
and muck soils, or on soils that respond to heavy phosphate fer-
tilization, as will be discussed later. Mixed grain may be offered,
but in limited amounts. Such a feed may be made up of corn-
meal, dried citrus pulp, wheat bran, an oilmeal and other similar
feeds which are reasonable in price. The amount of grain should
vary inversely with the amount and quality of forage accessible
to the heifers. Heifers should be in vigorous growing condition,
but not fat, at breeding age.

AGE AND SIZE TO BREED HEIFERS
Large vigorous heifers may be bred two or three months
younger than animals that are under-developed or in poor condi-
tion. The average ages recommended for service vary with the
size and rate of maturity of the different breeds, and are as
follows:

Breed Weights Age..to..Breed
Jersey 550 pounds 15 to 18 months
Guernsey 600 pounds 16 to 20 months
Ayrshire 650 pounds 17 to 21 months
Holstein 850 pounds 18 to 22 months
Brown Swiss 850 pounds 19 to 23 months

Sufficient fertilized pasture, home-grown forage and adequate
mineral matter, with limited allowance of concentrates, will allow
heifers to grow to good size. Extensive studies have shown
that within each breed the larger cows usually are the heavier
milk producers.







Dairy Cattle and Their Care


FEED FROM BREEDING TO CALVING TIME
The feeding practice after a heifer is with calf should be sim-
ilar to that before breeding age. Leafy forage may constitute
the main feed, supplemented with mineral matter, as outlined
below, and with grain limited according to the amount and
quality of forage available. Two months before freshening, the
heifer may be brought into the stanchions for extra grain. The
object of feeding extra grain is (a) to get the animal in condition
for maximum milk production after calving and (b) to accustom
her to the stanchion and barn routine before she must be milked.
This barn training makes a heifer more tractable and enables a
dairyman to anticipate calving time. Access to mineral supple-
ments needs especial attention prior to calving, particularly with
animals raised on light sandy and muck soils. Likewise, good
skeletal storage of calcium and phosphorus helps to prepare the
heifer for the first lactation.

MINERAL SUPPLEMENTS FOR CATTLE
Calves, rapidly growing heifers, pregnant animals and cows
in milk have a high requirement for mineral matter. Mineral
elements are needed by these animals to build the red portion
of blood, muscles and organs, the straw-colored part of the blood,
and the skeleton, as well as to stimulate appetite and to provide
for the minerals in milk.
Cattle never should be allowed to suffer from mineral short-
ages. Feeds should be selected with a knowledge of the nu-
trients which they provide for growing animals and milking
cows. Legumes usually contain from three to five times more
lime (calcium) than do grasses grown on the same land. Wheat
bran and several oilmeals are high in phosphorus content. Seeds
and grains usually contain less iron than do the leaves and
stems of plants, the amounts being related to available supply
in the soil.7 Heavily fertilized pastures provide larger amounts
of calcium and phosphorus to cattle than do unfertilized or na-
tive pastures.
It is advisable under most Florida conditions to give cattle
free access to additional mineral matter in a sheltered three-
compartment box, as shown in Figure 10. The first and second
compartments should contain common loose salt and steamed
bone meal, respectively.

Fla. Agr. Expt. Sta. Bul. 513, Minerals for Dairy and Beef Cattle.







Florida Agricultural Experiment Stations


Either of the following mineral mixtures may be used in the
third compartment.
Number 1 Number 2
Common Salt .......................100 lbs. Common Salt ...........-.....-- .. 50 lbs.
Red Oxide of Iron ............... 25 lbs. Bone Meal ......................... --- 50 lbs.
Pulverized Copper Sulfate.. 1 lb. Red Oxide of Iron .............. 25 lbs.
Cobalt Sulfate ......................-- 1 oz. Pulverized Copper Sulfate.. 1 lb.
Cobalt Sulfate ...-................. 1 oz.
Mineral supplement Number 1 is for general use with ani-
mals on light sandy and muck soils. The reduction in amount


Fig. 10.-A homemade three-compartment
mineral box allows cattle free access to com-
mon loose salt, steamed bonemeal (feeding
grade), and the iron-copper-cobalt supplement.
Separate access allows the animal to get the one
needed without forcing use of the other supple-
ments unnecessarily.

chew bones, leather, oyster shells and
presence of broken ribs and hips in any


of salt, and substitu-
tion with bone meal,
a d a p t s supplement
Number 2 for use
with animals on
areas near salt water
or where the drink-
ing water is brack-
ish. It is particular-
ly desirable that
the iron-copper-co-
balt supplement be
available for calves,
growing heifers and
pregnant cows at all
times, on areas that
are marginal or defi-
cient in any of these
mineral elements.
Steamed bone
meal (finely ground
feeding bone meal)
and defluorinated
rock phosphate sup-
ply both calcium and
phophorus in a safe,
read y available
f orm at relatively
low cost. Its use is
general with dairy
cows and also on
ranges where cattle
similar objects. The
dairy herd is an indi-







Dairy Cattle and Their Care 39

cation that bone meal should be added to the ration. Cattle
consume more mineral matter in late fall, winter and early spring
when on mature fibrous pasture herbage. Heavily milking cows
eat salt and bone meal in larger amounts than do heifers and dry
cows, while cows advancing in pregnancy use more of the iron-
copper-cobalt supplement than do cows recently fresh. The de-
fluorinated rock phosphate is palatable when mixed with com-
mon salt.

FACTORS AFFECTING MILK YIELD

SEASON OF CALVING AFFECTS YEARLY MILK YIELD

The influence of season of freshening on milk yield was meas-
ured by an analysis of 319 complete normal lactations of Jersey
cows milked twice daily in the Florida Station herd. These rec-
ords were obtained over a 16-year period and showed the gen-
eral trend of seasonal production with cows freshening at differ-
ent seasons.


Variations in dailJy mlk yield d o toi
M months In lactation
20
Calendar months -- --




-15-



p. -10




5
Months in Istation
1 2 3 4 5 6 7 8 9 10 11 12
Jan 72 rh Y pril d7 Jir July Mg S7t O0t Sr1 D1

Fig. 11.-Daily milk yield was stimulated during spring and early sum-
mer when young and succulent pasturage was available (see broken line).
Milk yield was depressed by advancing lactation (see solid line). The latter
influence was of greater magnitude than the former.

Cows fresh during the winter months (December to Febru-
ary) gave slightly more milk and were the more persistent pro-






Florida Agricultural Experiment Stations


ducers. Those calving in the autumn (October and November)
followed the first group very closely. Cows fresh in the summer
(June to September) ranked below these in milk yields, while
the spring calving group (March to May) produced the least.
Only very small differences were noted in the milk yields of the
cows fresh in autumn, winter and summer. However, the group
of cows freshening in spring produced less than did the groups
which calved during other times of the year.
The summer rainy season-a period of flush pasture-ex-
erted a noticeable influence in maintaining daily milk production
(see Fig. 11). The decline in daily milk yields was rapid just
after the close of the rainy season, when pasture turned dry
and vegetation became scanty and fibrous. The flush of pas-
ture during the rainy season appeared to stimulate milk produc-
tion-regardless of stage of lactation. However, the influence
of season of calving was of smaller magnitude than observed in
regions farther north where there are wider seasonal differences
in environment. A summary of average milk yields by cows
fresh at different seasons is given in Table 7.

TABLE 7.-AVERAGE YEARLY MILK PRODUCTION OF JERSEY COWS IN THE
FLORIDA STATION HERD, CALVING AT DIFFERENT SEASONS.

Season of Freshening Number of Lactations Relative Milk Production
Percent
Spring ................. 74 89.4
Summer .................. .. 104 98.1
Autumn .... ........... .. 70 99.8
W inter .......................... 71 100.0

AGE INFLUENCES MILK PRODUCTION
Studies of milk records in other parts of the United States
have shown that Jersey and Guernsey cows attain their peak of
milk production when five to eight years of age, and the larger,
later-maturing breeds at about one year older. The average
percentage of butterfat declines to a lesser degree with advanc-
ing age than does milk production.

LENGTH OF DRY PERIOD AFFECTS MILK YIELD
How long should cows be dry?
The answer to this question depends upon how the dry pe-
riod influences milk production and welfare in the next lactation,






Dairy Cattle and Their Care 41

and also upon the local demand for dairy products. In times of
local surplus of milk it may be desirable either to turn some
cows dry sooner or to cull out the less profitable animals. A
survey showed that Orlando dairymen turned their cows dry an
average of 46 days, Tampa dairymen up to 60 days, and the
average for the state was 55 days.
Influence of length of dry period upon subsequent lactation
was determined from records of cows in the Florida Station herd,
calving fairly regularly throughout different seasons of the year.
These records were divided into five groups: initial lactations
and those preceded by dry periods of 30 days or less, 31 to 60
days, 61 to 90 days and over 90 days.
The group following dry periods of 31 to 60 days showed
the highest average milk yield per lactation. Since this length
of dry period also is the one generally used by successful dairy-
men, it was used as a base with which to compare the production
of other classes. Cows dry less than 30 days produced 7.6 per-
cent less milk; those dry 61 to 90 days, 5.3 percent less; and those
dry longer than 90 days, 11.2 percent less milk than the basal
group. First-calf heifers produced 8.1 percent less than did the
group dry 31 to 60 days. It appears from this that the general
practice of allowing a dry period of 31 to 60 days favors optimum
milk production in commercial dairies. Klein and Woodward 8
confirmed one to two months as the optimum dry period, based
on a study of DHIA records.

MINERAL SUPPLEMENTS AS RELATED TO MILK YIELD
Rations adequate in the mineral elements required in nutri-
tion of dairy cows are not improved by the addition of more min-
eral matter. When dairy rations contain an adequate proportion
of high quality legume hay, corn silage and a grain mixture
which contains some wheat bran and an oil meal, no additional
mineral matter except salt is required by many cows in commer-
cial dairies. Even with the best of rations, however, high-pro-
ducing cows require attention to the mineral content of their
feeds. Common salt is deficient frequently. On acid soils or
where the roughages are entirely grasses rather than legumes,
calcium (lime) may be needed. Certain types of soils are low in
available phosphorus. Others may lack iron, copper and cobalt,
or there may be instances where two or more of these elements
may be deficient on the same land. Forages grown on some

SJournal of Dairy Science 26: 705-713. 1943.






Florida Agricultural Experiment Stations


muck soils may contain excess molybdenum which is toxic and
interferes with other mineral intakes. Under these circum-
stances cows respond to appropriate mineral supplements in the
rations, according to the extent of the condition.
The pasture and crop lands at the Florida Station were on
acid sandy soil, low in available lime. The forages supplied to
the dairy herd were mainly silage crops and pasture grasses
grown on these unlimed lands during that time. Under these
conditions the rations formerly fed were low in calcium content.
The calcium content of the rations was increased later by adding
2 percent of finely ground feeding steamed bone meal to the con-
centrates. The higher producing cows received a limited offering
of alfalfa hay. These changes provided sufficient calcium to meet
the requirements of Jersey cows in commercial dairies. More
recently, 1 percent each of bone meal and kalsite (marble dust)
were used instead of 2 percent of bone meal.
The average of 218 lactations while the cows received low
calcium rations was 4,856 pounds of milk. The 73 lactations on
rations adequate in calcium averaged 7,092 pounds of milk, or an
increase of 46 percent. While many of the animals appeared
only in one group, this difference compares closely with a sep-
arate study which involved lifetime production of 12 cows that
had complete normal lactations under each set of conditions.
Mixed dairy feeds marketed in the Southeast in recent years
contain supplementary bone meal and finely ground limestone,
so that in large part this calcium deficiency is being corrected.
Application of lime on improved pastures and mixed plantings
with legumes also provide this nutrient. Where rations are
home-mixed, it is desirable to consider the ingredients carefully
and to supplement the ration with such elements as may be
needed locally.
MANAGED MILKING
From research on milk secretion and methods of milking by
W. E. Petersen and associates at the Minnesota Station, milking
practices have evolved whereby the milk is obtained from the
cow in a minimum of time. The method has been described
briefly, as follows:
1. Prepare the cow's udder by washing with warm water
(about 125 degrees F.) or a good warm antiseptic solution.
Warm water stimulates the cow to release a hormone which
causes the udder to let down milk, requiring about 45 to 60 sec-
onds. Draw two streams from each teat into a strip cup to






Dairy Cattle and Their Care


check for infection in any quarter and hence to prevent spread
to other cows.
2. Begin milking one minute after stimulation of the udder.
Use the full-hand grasp in hand milking to prevent injury to teat
linings. In machine milking follow the manufacturer's instruc-
tions.
3. Milking should be completed in three or four minutes.
With machine milking, pull down on the teat cups when they
tend to crawl upward, to prevent closing off the teat canal from
the milk cistern.
4. Most cows can be stripped by machine. As the final step,
pull down on the teat cups while massaging the udder downward
to complete the operation. Few cows require hand stripping.
5. Remove the teat cups as soon as milk stops flowing to
prevent injury to the delicate lining of teats and milk cisterns.

FACTORS AFFECTING THE BUTTERFAT CONTENT
OF MILK
VARIATIONS IN THE BUTTERFAT CONTENT OF MILK
Butterfat content of the milk of any cow is affected by a
number of independent factors, most important of which is
heredity. The butterfat test of Jersey milk differs from that of
Holstein milk. Within a breed, the butterfat content likewise
is governed by heredity, with high, medium and low testing
individuals in every dairy breed. The milk of Holstein cows
on yearly Herd Improvement Registry test contained an aver-
age of 3.67 percent butterfat, whereas that of Jersey cows con-
tained 5.36 percent butterfat. The average for Guernsey records
is 4.80 percent butterfat, for Ayrshire 4.09 percent and for Brown
Swiss 4.05 percent butterfat. These are averages, about which
the various individuals of these different breeds vary. It is
possible to select strains within each of the breeds that transmit
a higher, or a lower, average butterfat content in milk. In fact,
by such selection the typical butterfat test of Friesian cattle in
the province of Friesland, the Netherlands, was increased more
than 0.75 percent within a 40-year period. The knowledge that
cows of equal size and milk yield produced butterfat more eco-
nomically in high testing milk was the reason for this breeding
practice.
Next in importance to heredity are the stage of lactation and
the season of the year (environment). The results of analyses







Florida Agricultural Experiment Stations


of two factors are shown in Fig. 12. The milk of purebred Jersey
cows in the Florida Station herd tended to test low in the first
two months after calving and increased gradually in richness as
the lactation advanced. This analysis was made in such a way
as to distribute evenly any seasonal influence.







5.0


S 14.5







1 2 5 6 7 r 1 12
71 1b March Acil ta7 JTne 8ft Ot Z1

Fig. 12.-The butterfat content of Jersey milk tends to increase in
cooler weather and also with advancing stage of lactation.

Regardless of stage of lactation, Jersey milk tended to be
richer in butterfat in the winter months and lower during the
summer months. These ranges in butterfat content tended to
follow those noted in more northerly latitudes. When cool
weather was incident with the latter stages of lactation, both
factors operated together for a high fat percentage in the milk,
and the opposite may occur with cows freshening in warm
weather.

RICHNESS OF MORNING AND EVENING MILK
A group of 1,785 butterfat tests was obtained from three con-
secutive milking taken from the monthly tests of Jersey cows
in the Station herd. It was observed from these that the average
morning milk tested 5.10 percent fat and the evening milk 5.72
percent fat in this herd. Occasionally the morning milk tested
higher than the evening milk. A 14-hour interval preceded the
morning milkings and 10-hour interval the evening milking.






Dairy Cattle and Their Care


Thus the lower butterfat tests were after the longer interval
between milkings. These observations are in accord with re-
sults of similar studies in other regions.
When the first butterfat test was above the average for the
Jersey breed, generally the next test tended to be lower. Fol-
lowing an extremely low test, the general trend was toward a
test in the succeeding milking near to, or above, average. Two
consecutive milkings from a single cow have varied from 2.4
to 8.1 percent fat, although variations of more than 2.0 percent
occurred infrequently.
When milk samples are being taken to determine the per-
centage of butterfat therein, either for the herd record of a single
cow or in regulatory milk inspection, it is well to remember that
the tests of morning and evening milk differ. Truly representa-
tive butterfat tests for such uses can be obtained only by using
both morning and evening milk from the same source.

AGE INFLUENCES AVERAGE BUTTERFAT TEST
Cows advancing in age usually yield milk of slightly lower
butterfat content than do younger animals. Records of 22 Jer-
sey cows in the Florida Station herd for eight or more lactations
showed this trend. These 22 cows had an average test of 5.17
percent butterfat in their first lactations, as compared with 4.72
percent in their eighth lactations. The decline in fat percentage
with age in Guernseys is similar to that with Jerseys. This de-
cline is less in the breeds producing milk of a lower butterfat
content.
EFFECT OF INSUFFICIENT FORAGES
When the intake of long leafy forage (hay, silage or pasture)
continued low over several weeks, the butterfat test of milk has
been observed to decrease gradually for two to four weeks and
remain low-often below established market standards. The
butterfat of Jersey and Guernsey milk has dropped as low as
one-half of normal. Such scarcity of forage has occurred during
drouths, with too many cows on a pasture, when pastures were
flooded, when cold weather or frosts have killed the grass, on
extremely young tender pastures and when no hay or silage was
fed. This subnormal butterfat test has been corrected by adding
four to six pounds of long hay or 15 pounds of corn silage daily,
or pasture containing some mature plants to the cow's feed.
Recovery usually was complete within two weeks, and often
earlier. This condition is caused by changes in the bacterial






Florida Agricultural Experiment Stations


functions in the cow's stomach, where the first steps of butterfat
synthesis take place. Large breeds require more leafy forage.

ECONOMIC PHASES OF DAIRYING
WHAT MAKES A SUCCESSFUL DAIRY FARM OPERATION?
Many factors under control of management affect the finan-
cial success of dairying. These have been pointed out in studies
of the farm dairy business in many states.
From a study of 106 farms in Montgomery County, New
York, during 1944-45 9, it was found that "high output of milk
per worker was an important key to production efficiency and
financial success-. High output of milk per man was obtained
principally by these practices:
1. Keeping moderately large herds, which made possible,
2. Spending less than the average amount of time per cow
to do the daily chores in the stable and yet
3. Having better-than-average producing cows."
Low producing cows have almost the same overhead costs
as do high producing cows. The barn space and equipment re-
quired are the same, and the labor requirement per cow is almost
as much. Thus as production per cow increases, overhead costs
and labor costs per 100 pounds of milk decrease.
This principle is shown in Table 8 from a study made in
North Carolina. These data show labor required in relation to
sales of milk per cow. Labor requirements and costs of milk
per 100 pounds decreased as production per cow increased. Cows
producing less than 5,000 pounds of milk had total costs 35
percent higher than those producing 6,200 pounds or more, and
labor requirements were 79 percent higher per 100 pounds of
milk.
Feed is the largest item of cost in milk production, often com-
prising more than half the total costs. In the past milk price
levels have been such that it was profitable to feed a concentrate
ration liberally for a higher level of milk production per cow.
In recent years there has been a trend toward more utilization
of pasture and home-grown forages as cheaper sources of feed.
However, Florida dairymen still feed the highest ratio of grain
and other concentrates per 100 pounds of milk of any state, and
o Farm Economics, Cornell University, No. 152, September, 1946. L. C.
Cunningham.







Dairy Cattle and Their Care 47

a further shift toward less concentrates and more home-grown
leafy forage may be advantageous.

TABLE 8.-RELATION OF MILK SALES PER COW TO HOURS OF LABOR AND
TOTAL COST PER 100 POUNDS OF MILK.*
Net Cost of
Milk Sold Number Average Labor Milk Sold Relative
Per Cow of Milk Sales 100 Pounds Per 100 Milk
Farms Per Cow of Milk Soldi Pounds Cost
Pounds Pounds Hours Percent
Less than
5,000 ...... 24 4,421 4.48 $3.58 121
5,000 to
6,199 ...... 34 5,580 3.33 $3.05 103
6,200 or
more ........ 31 6,991 2.50 $2.66 90
All Farms 89 5,868 3.14 $2.96 100

Adapted from R. E. L. Greene, North Carolina Agricultural Experiment Station Bulletin
Number 345. 1944.

SEASON OF CALVING IN RELATION TO MILK SALES
Dairymen generally try to have cows freshen at regular in-
tervals during the year, in order to meet the market demand for
milk. In areas having an important volume of tourist trade the
demand is seasonal and requires a larger proportion of cows in
heaviest milk production during that period.
The volume of whole milk sales per month reaches a low point
in August. Then it increases quite steadily through the follow-
ing spring. This seasonal trend, however, does not exactly coin-
cide with demand, as there is often a shortage of fluid milk when
schools open in the fall months. In some market areas a fall
premium plan applies to the pricing, and sometimes a produc-
tion base for Class 1 milk is determined during the fall months.
Both these devices function to stimulate fall production.
Management of the breeding program with respect to market
requirements for milk is reflected to a considerable extent in the
seasonal distribution of calvings, as shown in Table 9. These
data, derived from reports of dairymen in various parts of the
state, show the peak months of calving as August to December.
Peak milk production generally occurs about six weeks later
than calving and this would be in the months of October to
March. There has been a shift in the season of calving in recent
years from spring to fall months.







Florida Agricultural Experiment Stations


TABLE 9.-PERCENTAGE OF COWS AND HEIFERS FRESHENING BY MONTHS IN
FLORIDA.* (AVERAGE OF FIVE YEARS: 1952 TO 1956 INCLUSIVE).

Month Cows Freshening

Percent
January ....... .... ... .. .....-- ... .... .. ---- ...-.. 9.1
February --... ......... ...-.. -..... --- ...-- ... .. .............. 7.4
M arch ... ...-.. .... ......-..... ... .. ..... ........ 6.8
A pril ..... .. .. ........ -.. .....-....- ... .. .................... ...... 4.9
M ay .- -----... .. .......-.... -. .-- .. ............... ...--..-- 5.0
Jun e ----..... .........- ......-.. .... ... .. ..... ---.. ....... ......-- ..-..... 5.5
July ..- ----- ......... ..-.-. .... .. .. ........ -.. ............-- .....-- 6.7
A ugust ..- --- ..... ............-- .. ......-... ...- 11.0
Septem ber ............-......- ............ ...-- ...- ..... ...- ........... 11.6
O october .......................... .. .................. 11.7
N ovem ber ... .--- --- ...... .... ... .---.. .. .....-- ... 10.2
Decem ber ......... ..- .. ...............- ... ...- ... ... 10.1

Total ......... ....... ......-- ---............. .. ....... ... 100.0
Reported by Commercial and Noncommercial Dairymen to the Agricultural Marketing
Service, Orlando, Florida.

WHEN SHOULD A COW BE CULLED?
If a cow in a commercial dairy produces less than 5,500 pounds
of milk in a year, the manager needs to consider several factors:
(a) age of the cow; (b) average production of the herd; (c)
possibility of replacement with a better cow; (d) market demand
for Class 1 milk in the area; (e) health and reproductive history
of the cow.
In considering age and production, a cow two years old is
assumed to produce around 70 percent of her mature yearly
maximum. Most cows reach maximum production at five to
eight years of age, and then decline. A cow still breaking even
on costs at an advanced age may be retained another year in
the hope of securing a desirable heifer calf as a replacement.
If a marginal cow is under consideration, thought needs to be
given to the market needs for milk. Such a cow should be dis-
posed of when the need for milk is low or a more desirable cow
becomes available to replace her.
Replacing a low or average-producing cow by a higher pro-
ducer will be profitable under most conditions. If no replace-
ment is in sight, then the manager should calculate the effect of
immediate disposal on his net income. This involves an estimate
of the probable receipts and expenses of the cow.
Operating costs vary widely among herds, depending upon
production per cow, proportion of home-produced forage crops,







Dairy Cattle and Their Care


efficiency in the use of labor, rate of turnover of cows in the herd
and other lesser factors. However, in considering immediate
removal of a cow without a replacement available, only cash ex-
penses of feed, dairy supplies and services and depreciation of
the cow need be considered in the short run. Labor cost would
not be reduced by disposing of one or several cows on a special-
ized dairy farm, and silage and pasture produced for the disposed
cow might not be utilized.
Any cow that does not pay out-of-product costs should be
culled immediately, even if she is not replaced.
Some culling is beyond the planned control of the manager
and may be caused by failure of reproduction, accident, disease
or death.

RAISING VERSUS PURCHASING REPLACEMENTS
The largest cost items in producing a gallon of milk are feed,
labor and cow depreciation. Constructive attention to these
three major items is required to produce milk economically.
Previously most commercial dairies bought a large proper
tion of their replacements. However, it is advantageous to re-
tain heifers from at least the average and better cows in the
herd. This practice enables the dairyman to obtain a higher
average production per cow. It also reduces the chance of bring-
ing in disease. Home-raised replacements also are kept longer
in the herd, which substantially reduces the cow depreciation
cost per gallon of milk.
Data on the rate of turnover or replacement of cows were
obtained in 1945 and 1947 from about 60 commercial dairies in
Florida. Most of these dairymen were buying the majority of
replacements. These cows remained in the herds about 21/2
years in the Miami area and about three years in the Jackson-
ville, Orlando and Tampa areas.
A survey of 105 dairies in the Florida peninsula in 1953,
where one third of the cows were raised, indicated a useful life
of 4.8 years.10 In each survey, cows in the larger dairies had a
shorter period of usefulness than in the smaller dairies.
Cows in a sample of Florida dairies maintained with raised
replacements had an average life span of 6.7 years, or about
4.7 years of productive lifetime. See Table 10.

10 Eldon D. Smith, N. K. Roberts and Wm. G. O'Regan. Milk Production
Trends in the Florida Peninsula. Agr. Econ. Series No. 55-9.







Florida Agricultural Experiment Stations


A survey covering 763 dairy farms in Connecticut found that
home-raised cows stayed in the milking herd an average of 4.0
years, in contrast with 2.6 years in herds buying replacements.11
The longer period of usefulness of raised replacements, even
if their first cost is somewhat higher, may make their cost per
year of service and per 100 pounds of milk less than with pur-
chased cows. This is because their cost is spread over a longer
period of useful life and a higher total milk production.
Each dairyman in deciding whether to raise or purchase
replacements should consider his position as to available land,
pasture and labor. If resources are limited, dividing them be-
tween the milking herd and the raising of heifers may result in
less milk produced for sale. However, if facilities are available,
raised replacements will result in a better herd in the long run.

AVERAGE USEFUL LIFE SPAN AND REASON FOR
DISPOSAL OF DAIRY CATTLE
Records of life span have been obtained from 13 dairies in
Florida on which most of their replacements were raised. These
records showed birth dates and disposal dates for each cow, to-
gether with the reason for disposal. The life span of 2,961 cows
with the average life expectancy at different ages is shown in
Table 10. No cows were included which did not attain an age
of two years and come into the milking herd. Thus, mortality
experienced in raising calves and heifers is not considered in
Table 10.
All cows averaged 6.6 years of life, or about 4.6 years of use-
fulness in the milking herd. At 6 years of age, 48 percent of the
original number of cows had left the herds. Cows which reached
six years of age, however, lived to an average of 8.8 years and
thus had an additional life expectancy of 2.8 years. At 10 years
old only 14 percent of the original number remained, with an
additional life expectancy of 1.7 years. A large number of
observations is needed to be conclusive in the higher age groups,
but these indications should be helpful to dairymen, especially
in purchasing high priced cattle, to estimate how much longer
a desirable healthy cow of a given age may be expected to stay
in the herd. It will be noted that a very high rate of loss or
culling occurs at ages from three to five years, with the highest
rate in the four-year group. Cows that are good producers fre-
11 Published in Hoard's Dairyman, January 10, 1947. Data on 763 Dairy
Farms, Connecticut.








Dairy Cattle and Their Care


quently have to pay the losses incurred by any younger animals
that have proven unprofitable.

TABLE 10.-AVERAGE USEFUL LIFE SPAN OF 2,961 FLORIDA DAIRY COWS
(EXCLUDING COWS SOLD FOR DAIRY OR BREEDING PURPOSES AND THOSE NOT
REACHING TWO YEARS OF AGE).

Number of Cows I Average Anticipated
Age Left Herd Age at Usefulness at
Living* Percent During Disposal Different
of Total Year Ages
Years Number Percent Number Years Years
2.0 2,961 100.0 170 6.6 4.6
3.0 2,791 94.3 384 6.9 3.9
4.0 2,407 81.3 429 7.4 3.4
5.0 1,978 66.8 435 8.1 3.1
6.0 1,543 52.1 344 8.8 2.8
7.0 1,199 40.5 302 9.5 2.5
8.0 897 30.3 273 10.2 2.2
9.0 624 21.1 206 11.0 2.0
10.0 418 14.1 151 11.7 1.7
11.0 267 9.0 121 12.5 1.5
12.0 146 4.9 73 13.4 1.4
13.0** 73 2.5 38 14.4 1.4
14.0** 35 1.2 15 15.5 1.5
15.0** 20 .7 8 16.3 1.3
16.0** 12 .4 9 16.9 .9
17.0** 3 .1 0 18.4 1.4
18.0"** 3 .1 2 18.4 .4
19.0** 1 .03 1 19.2 .2

Of 2,961 original animals as two year olds, 170 left the herd during the first year, with
2,791 remaining as three year olds and so on consecutively.
** Insufficient numbers to be reliable.

Reasons for replacements of dairy cows were known in some
cases where exact ages were unknown, thus resulting in a larger
number of observations for "reasons for disposal". The princi-
pal reasons for 3,447 dairy cows leaving the herds are shown in
Table 11. Cows sold for dairy or breeding purposes were ex-
cluded.
Low production was the reason most frequently given for
disposal of live cows and accounted for 25 percent of the disposals.
Mastitis and udder trouble were responsible for 19 percent of
the cows removed, and reproductive troubles for 16 percent.
Various combinations of the above reasons resulted in the dis-
posal of 3 percent, or a total of 63 percent from these four causes.
Five percent of the cows were removed because of age and 3
percent because of accidents or injuries. The exact reason is
sometimes difficult to ascribe, since a primary condition some-
times leads to a secondary cause which is given as the final reason
for removal from the herd.








52 Florida Agricultural Experiment Stations

TABLE 11.-PRINCIPAL REASONS FOR DISPOSAL OF 3,447 FLORIDA DAIRY
COWS, AS GIVEN BY DAIRYMEN (EXCLUDING COWS SOLD FOR DAIRY PURPOSES
AND THOSE NOT REACHING TWO YEARS OF AGE).

Reasons for Disposal Number of Percent of
Cows Total

Mastitis and Udder Trouble .............. 681 19.8
Low Production .......................-........ ....... 870 25.2
Reproductive Trouble ............................... 545 15.8
Combinations of Above ............................. 97 2.8
Diseases ....................--.... ...- ............. 102 3.0
Old Age .......................................... ..... 161 4.7
Accidents and Injuries ---.....................-----.......----.. 86 2.5
Other Reasons ............. ................ ............. 80 2.3
U nstated .......................... .... ..-... ........ 335 9.7


Total Disposals While Living ........... 2,957 85.8


Deaths from Diseases:
Johne's Disease ..........-.................--........ 37
Milk Fever ... ..... ............................ .. 24
M astitis ... .................. ............. ........ 37
Anaplasm osis ..................-..........-... ----.... 35
Acetonem ia ......................--.....---- ......... -- 19
O their .......... ........ ................ ............ 74


Total from Diseases ....----.. ....-....... 226


Deaths from Other Causes:
Reproductive Trouble .........-............. 81
Accidents, Poisoning, Hardware ........... 60
Old A ge ...--..... .................. .........--- .... 17
O their ......................... ........... ..-- .. 39
Unknown ......-............................-....--- 67


Total Deaths ...............................-.... ...... 490 14.2

Total Disposals ...............- .. .......- ..-.... 3,447 100.0
Source: From unpublished data of the Florida Agricultural Experiment Station. Pre-
liminary.

Death caused the loss of 14 percent of all cows removed.
Various diseases, reproductive troubles, accidents and old age
were the important reasons for death.
During the fiscal year of 1957-1958, 52 dairy cows were sal-
vaged for beef from five of the cooperating dairy herds. The
returns per cow varied widely, according to their weight and
character. There was a 2.6 percent mortality of cows in these
herds during the year. The range in salvage values for that
year is shown in Table 12.







Dairy Cattle and Their Care


TABLE 12.-AVERAGE SALVAGE VALUE OF 52 Cows FROM FIVE COOPERATING
DAIRIES, 1957-1958.

Value Class Number of Cows Total Value Average Value

$ 60- 69 ............. 1 $ 67.45 $ 67.45
70- 79 .............. 2 145.71 72.85
80- 89 ................ 2 166.30 83.15
90- 99 .........- .... 7 660.98 94.43
100-109 ................ 3 317.58 105.86
110-119 ................ 4 465.17 116.29
120-129 ............ 12 1,501.14 125.10
130-139 ................ 5 669.54 133.91
140-149 ................ 4 572.49 143.12
150-159 ............... 5 778.12 155.62
160-169 .........-... 3 490.94 163.65
170-179 .............. 1 172.32 172.32
180-189 .............. 1 187.04 187.04
190-199 ............... 0
200-239 ........... .. 2 458.32 229.16

Total or Average 52 $6,653.10 $127.94


DEPRECIATION OF DAIRY COWS
No fixed rate of depreciation can be assigned to dairy cows
that will apply under all conditions. Depreciation rates change
with changes in the various factors which enter into depreciation
costs. These factors are:
1. Initial cost of cow at first calving or at time of purchase.
2. Number of years she will remain in the herd. This is ap-
parently longer for raised than for purchased animals. Pur-
chased replacements seem to have a service life after purchase
of about three years and raised cows about 4.6 years after first
freshening.
3. Salvage value, which fluctuates with beef prices.
4. Death rate. This should be included in the depreciation
rate to avoid a separate calculation for deaths. Cows eliminated
by death are a total loss to the herd, and including average death
rates in depreciation makes allowances for this cost. In 1945
the death rate was found to be about 3.9 per 100 cows in a num-
ber of commercial dairies in the state which were purchasing
most of their replacements. It was 2.6 percent in 5 herds raising
replacements in 1957-1958. The death rate may fluctuate with
various conditions.







Florida Agricultural Experiment Stations


When the initial cost, service life, salvage value and death
rate of dairy cows are known, the depreciation rate may be cal-
culated by the following formula:
[ Deprecia-
Cost 1 Deaths per 100 tion cost
x Salvage Value = per year
No. of years No. years 100 in
of use of use dollars

With assumed values, a method of calculating the rate of
depreciation for a dairy herd is illustrated below:
Average value or cost per cow ........ .......................... ...$200
Average number of years of service life .............................. 4.0
Average salvage value .................-- -... .......... .......... ....$ 85
Death rate per 100 cows per year ... .............................. 3.9
$200 ) x $85 = Depreciation per year
4 4 100

$50 ( .250 .039) x $85 or
$50 -($21.25 $3.32) or
$50 -$17.93 = $32.07, average depreciation cost per year per cow.
The depreciation cost in dollars divided by the average initial
cost of a cow and multiplied by 100 gives the annual rate of de-
preciation in percent.
$32.07
X 100 = 16.0 percent
$200.00
Should any of the factors affecting depreciation cost change,
the rate and amount will change. Thus for a cow costing $300,
the annual depreciation would be $57.06, or 19.0 percent of her
cost, if other assumptions remain constant. For $150 cows with
4.0 years of service life and $85 salvage value, the depreciation
cost per year would be $19.56, or 13.0 percent.
No interest has been included in these calculations. Interest
costs would vary directly with the cost of the cow.
The effect of a cow's useful lifespan and of initial cost on
depreciation cost is shown in Table 13. The depreciation cost
per gallon has been calculated at three different levels of pro-
ductivity.
Thus, it can be seen that a longer useful life span is important
in keeping down annual depreciation cost per cow. Adding a year
to a cow's productive life spreads the cost over a longer period.
The higher the initial cost of a cow, the higher her annual
depreciation, assuming a fixed life span and salvage value. De-







Dairy Cattle and Their Care


preciation cost per year increases more than proportionately
with increasing initial cost. This, however, does not point toward
the use of low grade cows, as their productivity may also be low
and other costs higher.

TABLE 13.-EFFECT OF USEFUL LIFE AND INITIAL COST OF A COW ON
DEPRECIATION COST PER GALLON OF MILK AT VARYING RATES OF PRODUCTIV-
ITY.*

Useful Assumed Depreciation Depreciation Cost Per Gallon
Life Valuation Cost Per Year 600 800 1,000
(Years) I Gallons Gallons Gallons
Effect of Useful Life

1.0 $200 $118.32 $0.197 $0.148 $0.118
2.0 200 60.82 .101 .076 .061
3.0 200 41.65 .069 .052 .042
4.0 200 32.06 .053 .040 .032
5.0 200 26.32 .044 .033 .026
Effect of Initial Cost


4.0 $100 $ 7.06 $0.012 $0.009 $0.007
4.0 150 19.56 .033 .024 .020
4.0 200 32.06 .053 .040 .032
4.0 250 44.56 i .074 .056 .045
4.0 300 57.06 .095 .071 .057
4.0 350 69.56 .116 .087 .070
Assumed Salvage Value, $85.

At any given life span and initial value of a cow, the depreci-
ation cost per gallon decreases directly as production per year
increases. The herdsman should strive for cows of higher pro-
duction and make every effort to extend their profitable produc-
tive life to obtain the lowest depreciation cost per gallon of milk
produced.
ACKNOWLEDGMENTS

Dairy herd records prior to June 1928 were accumulated by Professor
John M. Scott, formerly Animal Industrialist and Vice-Director of the
Florida Agricultural Experiment Station. Herdsmen Clarence M. Robin-
son, Burdette Schee, Herman L. Somers and many student assistants were
responsible for completeness and accuracy of later records. Florida dairy-
men and breeders of dairy cattle over the United States and Canada co-
operated with records concerning useful life span and causes of losses of
dairy animals under practical conditions. Recent investigations of Drs.
S. P. Marshall and J. M. Wing were a basis for some calf feeding recom-
mendations. Certain photographs were taken by J. Francis Cooper and
Ralph J. Sneeringer. The photograph in Figure 8 is from 4-H Dairy Club
work in Orange County.




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